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path: root/drivers/usb/host/xhci-ring.c
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2009-12-11USB: xhci: Fix command completion after a drop endpoint.Sarah Sharp
The xHCI driver issues a Configure Endpoint command for two reasons: - a new configuration or alternate interface setting is selected - a quirky Fresco Logic prototype requires the command after a Reset Endpoint command. The xHCI driver only waits on the command in the first case. When a configure endpoint command completes, the driver needs to know why the command was generated. When the driver only supported selecting an initial configuration, the check was simple. Unfortunately that check doesn't work now that the driver supports alternate interfaces. If an endpoint must be dropped (because it's not in the new alternate setting) and no new endpoints are added, the math involving xhci_last_valid_endpoint() will assign -1 to an unsigned integer and cause an out-of-bounds array access. Move the check for the quirky hardware sooner and avoid the bad array access. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Handle errors that cause endpoint halts.Sarah Sharp
The xHCI 0.95 and 0.96 specification defines several transfer buffer request completion codes that indicate a USB transaction error occurred. When a stall, babble, transaction, or split transaction error completion code is set, the xHCI has halted that endpoint ring. Software must issue a Reset Endpoint command and a Set Transfer Ring Dequeue Pointer command to clean up the halted ring. The USB device driver is supposed to call into usb_reset_endpoint() when an endpoint stalls. That calls into the xHCI driver to issue the proper commands. However, drivers don't call that function for the other errors that cause the xHC to halt the endpoint ring. If a babble, transaction, or split transaction error occurs, check if the endpoint context reports a halted condition, and clean up the endpoint ring if it does. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Return success for vendor-specific info codes.Sarah Sharp
An xHCI host controller manufacturer can choose to implement several vendor-specific informational completion codes. These are all to be treated like a successful transfer completion. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Return -EPROTO on a split transaction error.Sarah Sharp
When the xHCI hardware says a transfer completed with a split transaction error, set the URB status to -EPROTO. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Set transfer descriptor size field correctly.Sarah Sharp
The transfer descriptor (TD) is a series of transfer request buffers (TRBs) that describe the buffer pointer, length, and other characteristics. The xHCI controllers want to know an estimate of how long the TD is, for caching reasons. In each TRB, there is a "TD size" field that provides a rough estimate of the remaining buffers to be transmitted, including the buffer pointed to by that TRB. The TD size is 5 bits long, and contains the remaining size in bytes, right shifted by 10 bits. So a remaining TD size less than 1024 would get a zero in the TD size field, and a remaining size greater than 32767 would get 31 in the field. This patches fixes a bug in the TD_REMAINDER macro that is triggered when the URB has a scatter gather list with a size bigger than 32767 bytes. Not all host controllers pay attention to the TD size field, so the bug will not appear on all USB 3.0 hosts. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Add tests for TRB address translation.Sarah Sharp
It's not surprising that the transfer request buffer (TRB) physical to virtual address translation function has bugs in it, since I wrote most of it at 4am last October. Add a test suite to check the TRB math. This runs at memory initialization time, and causes the driver to fail to load if the TRB math fails. Please excuse the excessively long lines in the test vectors; they can't really be made shorter and still be readable. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Remove unused HCD statistics code.Sarah Sharp
CONFIG_USB_HCD_STAT was used in an abandoned patch to track host controller throughput statistics. Since CONFIG_USB_HCD_STAT will never be defined, remove code that can never run. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Add watchdog timer for URB cancellation.Sarah Sharp
In order to giveback a canceled URB, we must ensure that the xHCI hardware will not access the buffer in an URB. We can't modify the buffer pointers on endpoint rings without issuing and waiting for a stop endpoint command. Since URBs can be canceled in interrupt context, we can't wait on that command. The old code trusted that the host controller would respond to the command, and would giveback the URBs in the event handler. If the hardware never responds to the stop endpoint command, the URBs will never be completed, and we might hang the USB subsystem. Implement a watchdog timer that is spawned whenever a stop endpoint command is queued. If a stop endpoint command event is found on the event ring during an interrupt, we need to stop the watchdog timer with del_timer(). Since del_timer() can fail if the timer is running and waiting on the xHCI lock, we need a way to signal to the timer that everything is fine and it should exit. If we simply clear EP_HALT_PENDING, a new stop endpoint command could sneak in and set it before the watchdog timer can grab the lock. Instead we use a combination of the EP_HALT_PENDING flag and a counter for the number of pending stop endpoint commands (xhci_virt_ep->stop_cmds_pending). If we need to cancel the watchdog timer and del_timer() succeeds, we decrement the number of pending stop endpoint commands. If del_timer() fails, we leave the number of pending stop endpoint commands alone. In either case, we clear the EP_HALT_PENDING flag. The timer will decrement the number of pending stop endpoint commands once it obtains the lock. If the timer is the tail end of the last stop endpoint command (xhci_virt_ep->stop_cmds_pending == 0), and the endpoint's command is still pending (EP_HALT_PENDING is set), we assume the host is dying. The watchdog timer will set XHCI_STATE_DYING, try to halt the xHCI host, and give back all pending URBs. Various other places in the driver need to check whether the xHCI host is dying. If the interrupt handler ever notices, it should immediately stop processing events. The URB enqueue function should also return -ESHUTDOWN. The URB dequeue function should simply return the value of usb_hcd_check_unlink_urb() and the watchdog timer will take care of giving the URB back. When a device is disconnected, the xHCI hardware structures should be freed without issuing a disable slot command (since the hardware probably won't respond to it anyway). The debugging polling loop should stop polling if the host is dying. When a device is disconnected, any pending watchdog timers are killed with del_timer_sync(). It must be synchronous so that the watchdog timer doesn't attempt to access the freed endpoint structures. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: xhci: Handle URB cancel, complete and resubmit race.Sarah Sharp
In the old code, there was a race condition between the stop endpoint command and the URB submission process. When the stop endpoint command is handled by the event handler, the endpoint ring is assumed to be stopped. When a stop endpoint command is queued, URB submissions are to not ring the doorbell. The old code would check the number of pending URBs to be canceled, and would not ring the doorbell if it was non-zero. However, the following race condition could occur with the old code: 1. Cancel an URB, add it to the list of URBs to be canceled, queue the stop endpoint command, and increment ep->cancels_pending to 1. 2. The URB finishes on the HW, and an event is enqueued to the event ring (at the same time as 1). 3. The stop endpoint command finishes, and the endpoint is halted. An event is queued to the event ring. 4. The event handler sees the finished URB, notices it was to be canceled, decrements ep->cancels_pending to 0, and removes it from the to be canceled list. 5. The event handler drops the lock and gives back the URB. The completion handler requeues the URB (or a different driver enqueues a new URB). This causes the endpoint's doorbell to be rung, since ep->cancels_pending == 0. The endpoint is now running. 6. A second URB is canceled, and it's added to the canceled list. Since ep->cancels_pending == 0, a new stop endpoint command is queued, and ep->cancels_pending is incremented to 1. 7. The event handler then sees the completed stop endpoint command. The handler assumes the endpoint is stopped, but it isn't. It attempts to move the dequeue pointer or change TDs to cancel the second URB, while the hardware is actively accessing the endpoint ring. To eliminate this race condition, a new endpoint state bit is introduced, EP_HALT_PENDING. When this bit is set, a stop endpoint command has been queued, and the command handler has not begun to process the URB cancellation list yet. The endpoint doorbell should not be rung when this is set. Set this when a stop endpoint command is queued, clear it when the handler for that command runs, and check if it's set before ringing a doorbell. ep->cancels_pending is eliminated, because it is no longer used. Make sure to ring the doorbell for an endpoint when the stop endpoint command handler runs, even if the canceled URB list is empty. All canceled URBs could have completed and new URBs could have been enqueued without the doorbell being rung before the command was handled. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-11-17USB: xhci: Fix TRB physical to virtual address translation.Sarah Sharp
The trb_in_td() function in the xHCI driver is supposed to translate a physical transfer buffer request (TRB) into a virtual pointer to the ring segment that TRB is in. Unfortunately, a mistake in this function may cause endless loops as the driver searches through the linked list of ring segments over and over again. Fix a couple bugs that may lead to loops or bad output: 1. Bail out if we get a NULL pointer when translating the segment's private structure and the starting DMA address of the segment chunk. If this happens, we've been handed a starting TRB pointer from a different ring. 2. Make sure the function works when there's multiple segments in the ring. In the while loop to search through the ring segments, use the current segment variable (cur_seg), rather than the starting segment variable (start_seg) that is passed in. 3. Stop searching the ring if we've run through all the segments in the ring. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Support USB hubs.Sarah Sharp
For a USB hub to work under an xHCI host controller, the xHC's internal scheduler must be made aware of the hub's characteristics. Add an xHCI hook that the USB core will call after it fetches the hub descriptor. This hook will add hub information to the slot context for that device, including whether it has multiple TTs or a single TT, the number of ports on the hub, and TT think time. Setting up the slot context for the device is different for 0.95 and 0.96 xHCI host controllers. Some of the slot context reserved fields in the 0.95 specification were changed into hub fields in the 0.96 specification. Don't set the TT think time or number of ports for a hub if we're dealing with a 0.95-compliant xHCI host controller. The 0.95 xHCI specification says that to modify the hub flag, we need to issue an evaluate context command. The 0.96 specification says that flag can be set with a configure endpoint command. Issue the correct command based on the version reported by the hardware. This patch does not add support for multi-TT hubs. Multi-TT hubs expose a single TT on alt setting 0, and multi-TT on alt setting 1. The xHCI driver can't handle setting alternate interfaces yet. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Fix command wait list handling.Sarah Sharp
In the xHCI driver, configure endpoint commands that are submitted to the hardware may involve one of two data structures. If the configure endpoint command is setting up a new configuration or modifying max packet sizes, the data structures and completions are statically allocated in the xhci_virt_device structure. If the command is being used to set up streams or add hub information, then the data structures are dynamically allocated, and placed on a device command waiting list. Break out the code to check whether a completed command is in the device command waiting list. Fix a subtle bug in the old code: continue processing the command if the command isn't in the wait list. In the old code, if there was a command in the wait list, but it didn't match the completed command, the completed command event would be dropped. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Change how xHCI commands are handled.Sarah Sharp
Some commands to the xHCI hardware cannot be allowed to fail due to out of memory issues or the command ring being full. Add a way to reserve a TRB on the command ring, and make all command queueing functions indicate whether they are using a reserved TRB. Add a way to pre-allocate all the memory a command might need. A command needs an input context, a variable to store the status, and (optionally) a completion for the caller to wait on. Change all code that assumes the input device context, status, and completion for a command is stored in the xhci virtual USB device structure (xhci_virt_device). Store pending completions in a FIFO in xhci_virt_device. Make the event handler for a configure endpoint command check to see whether a pending command in the list has completed. We need to use separate input device contexts for some configure endpoint commands, since multiple drivers can submit requests at the same time that require a configure endpoint command. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Endpoint representation refactoring.Sarah Sharp
The xhci_ring structure contained information that is really related to an endpoint, not a ring. This will cause problems later when endpoint streams are supported and there are multiple rings per endpoint. Move the endpoint state and cancellation information into a new virtual endpoint structure, xhci_virt_ep. The list of TRBs to be cancelled should be per endpoint, not per ring, for easy access. There can be only one TRB that the endpoint stopped on after a stop endpoint command (even with streams enabled); move the stopped TRB information into the new virtual endpoint structure. Also move the 31 endpoint rings and temporary ring storage from the virtual device structure (xhci_virt_device) into the virtual endpoint structure (xhci_virt_ep). Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Support interrupt transfers.Sarah Sharp
Interrupt transfers are submitted to the xHCI hardware using the same TRB type as bulk transfers. Re-use the bulk transfer enqueueing code to enqueue interrupt transfers. Interrupt transfers are a bit different than bulk transfers. When the interrupt endpoint is to be serviced, the xHC will consume (at most) one TD. A TD (comprised of sg list entries) can take several service intervals to transmit. The important thing for device drivers to note is that if they use the scatter gather interface to submit interrupt requests, they will not get data sent from two different scatter gather lists in the same service interval. For now, the xHCI driver will use the service interval from the endpoint's descriptor (bInterval). Drivers will need a hook to poll at a more frequent interval. Set urb->interval to the interval that the xHCI hardware will use. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Set -EREMOTEIO when xHC gives bad transfer length.Sarah Sharp
The xHCI hardware reports the number of bytes untransferred for a given transfer buffer. If the hardware reports a bytes untransferred value greater than the submitted buffer size, we want to play it safe and say no data was transferred. If the driver considers a short packet to be an error, remember to set -EREMOTEIO. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Check URB_SHORT_NOT_OK before setting short packet status.Sarah Sharp
Make sure that the driver that submitted the URB considers a short packet an error before setting -EREMOTEIO during a short control transfer. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Check URB's actual transfer buffer size.Sarah Sharp
Make sure that the amount of data the xHC says was transmitted is less than or equal to the size of the requested transfer buffer. Before, if the host controller erroneously reported that the number of bytes untransferred was bigger than the buffer in the URB, urb->actual_length could be set to a very large size. Make sure urb->actual_length <= urb->transfer_buffer_length. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Don't touch xhci_td after it's freed.Sarah Sharp
On a successful transfer, urb->td is freed before the URB is ready to be given back to the driver. Don't touch urb->td after it's freed. This bug would have only shown up when xHCI debugging was turned on, and the freed memory was quickly reused for something else. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Handle babbling endpoints correctly.Sarah Sharp
The 0.95 xHCI spec says that non-control endpoints will be halted if a babble is detected on a transfer. The 0.96 xHCI spec says all types of endpoints will be halted when a babble is detected. Some hardware that claims to be 0.95 compliant halts the control endpoint anyway. When a babble is detected on a control endpoint, check the hardware's output endpoint context to see if the endpoint is marked as halted. If the control endpoint is halted, a reset endpoint command must be issued and the transfer ring dequeue pointer needs to be moved past the stopped transfer. Basically, we treat it as if the control endpoint had stalled. Handle bulk babbling endpoints as if we got a completion event with a stall completion code. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Make TRB completion code comparison readable.Sarah Sharp
Use trb_comp_code instead of getting the completion code from the transfer event every time. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Add quirk for Fresco Logic xHCI hardware.Sarah Sharp
This Fresco Logic xHCI host controller chip revision puts bad data into the output endpoint context after a Reset Endpoint command. It needs a Configure Endpoint command (instead of a Set TR Dequeue Pointer command) after the reset endpoint command. Set up the input context before issuing the Reset Endpoint command so we don't copy bad data from the output endpoint context. The HW also can't handle two commands queued at once, so submit the TRB for the Configure Endpoint command in the event handler for the Reset Endpoint command. Devices that stall on control endpoints before a configuration is selected will not work under this Fresco Logic xHCI host controller revision. This patch is for prototype hardware that will be given to other companies for evaluation purposes only, and should not reach consumer hands. Fresco Logic's next chip rev should have this bug fixed. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Handle stalled control endpoints.Sarah Sharp
When a control endpoint stalls, the next control transfer will clear the stall. The USB core doesn't call down to the host controller driver's endpoint_reset() method when control endpoints stall, so the xHCI driver has to do all its stall handling for internal state in its interrupt handler. When the host stalls on a control endpoint, it may stop on the data phase or status phase of the control transfer. Like other stalled endpoints, the xHCI driver needs to queue a Reset Endpoint command and move the hardware's control endpoint ring dequeue pointer past the failed control transfer (with a Set TR Dequeue Pointer or a Configure Endpoint command). Since the USB core doesn't call usb_hcd_reset_endpoint() for control endpoints, we need to do this in interrupt context when we get notified of the stalled transfer. URBs may be queued to the hardware before these two commands complete. The endpoint queue will be restarted once both commands complete. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Support full speed devices.Sarah Sharp
Full speed devices have varying max packet sizes (8, 16, 32, or 64) for endpoint 0. The xHCI hardware needs to know the real max packet size that the USB core discovers after it fetches the first 8 bytes of the device descriptor. In order to fix this without adding a new hook to host controller drivers, the xHCI driver looks for an updated max packet size for control endpoints. If it finds an updated size, it issues an evaluate context command and waits for that command to finish. This should only happen in the initialization and device descriptor fetching steps in the khubd thread, so blocking should be fine. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Configure endpoint code refactoring.Sarah Sharp
Refactor out the code issue, wait for, and parse the event completion code for a configure endpoint command. Modify it to support the evaluate context command, which has a very similar submission process. Add functions to copy parts of the output context into the input context (which will be used in the evaluate context command). Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: xhci: Work around for chain bit in link TRBs.Sarah Sharp
Different sections of the xHCI 0.95 specification had opposing requirements for the chain bit in a link transaction request buffer (TRB). The chain bit is used to designate that adjacent TRBs are all part of the same scatter gather list that should be sent to the device. Link TRBs can be in the middle, or at the beginning or end of these chained TRBs. Sections 4.11.5.1 and 6.4.4.1 both stated the link TRB "shall have the chain bit set to 1", meaning it is always chained to the next TRB. However, section 4.6.9 on the stop endpoint command has specific cases for what the hardware must do for a link TRB with the chain bit set to 0. The 0.96 specification errata later cleared up this issue by fixing the 4.11.5.1 and 6.4.4.1 sections to state that a link TRB can have the chain bit set to 1 or 0. The problem is that the xHCI cancellation code depends on the chain bit of the link TRB being cleared when it's at the end of a TD, and some 0.95 xHCI hardware simply stops processing the ring when it encounters a link TRB with the chain bit cleared. Allow users who are testing 0.95 xHCI prototypes to set a module parameter (link_quirk) to turn on this link TRB work around. Cancellation may not work if the ring is stopped exactly on a link TRB with chain bit set, but cancellation should be a relatively uncommon case. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Stall handling bug fixes.Sarah Sharp
Correct the xHCI code to handle stalls on USB endpoints. We need to move the endpoint ring's dequeue pointer past the stalled transfer, or the HW will try to restart the transfer the next time the doorbell is rung. Don't attempt to clear a halt on an endpoint if we haven't seen a stalled transfer for it. The USB core will attempt to clear a halt on all endpoints when it selects a new configuration. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Support for 64-byte contextsJohn Youn
Adds support for controllers that use 64-byte contexts. The following context data structures are affected by this: Device, Input, Input Control, Endpoint, and Slot. To accommodate the use of either 32 or 64-byte contexts, a Device or Input context can only be accessed through functions which look-up and return pointers to their contained contexts. Signed-off-by: John Youn <johnyoun@synopsys.com> Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Handle babble errors on transfers.Sarah Sharp
Pass back a babble error when this error code is seen in the transfer event TRB. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Make debugging more verbose.Sarah Sharp
Add more debugging to the irq handler, slot context initialization, ring operations, URB cancellation, and MMIO writes. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Correct Event Handler Busy flag usage.Sarah Sharp
The Event Handler Busy bit in the event ring dequeue pointer is write 1 to clear. Fix the interrupt service routine to clear that bit after the event handler has run. xhci_set_hc_event_deq() is designed to update the event ring dequeue pointer without changing any of the four reserved bits in the lower nibble. The event handler busy (EHB) bit is write one to clear, so the new value must always contain a zero in that bit in order to preserve the EHB value. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Handle short control packets correctly.Sarah Sharp
When there is a short packet on a control transfer, the xHCI host controller hardware will generate two events. The first event will be for the data stage TD with a completion code for a short packet. The second event will be for the status stage with a successful completion code. Before this patch, the xHCI driver would giveback the short control URB when it received the event for the data stage TD. Then it would become confused when it saw a status stage event for the endpoint for an URB it had already finished processing. Change the xHCI host controller driver to wait for the status stage event when it receives a short transfer completion code for a data stage TD. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Represent 64-bit addresses with one u64.Sarah Sharp
There are several xHCI data structures that use two 32-bit fields to represent a 64-bit address. Since some architectures don't support 64-bit PCI writes, the fields need to be written in two 32-bit writes. The xHCI specification says that if a platform is incapable of generating 64-bit writes, software must write the low 32-bits first, then the high 32-bits. Hardware that supports 64-bit addressing will wait for the high 32-bit write before reading the revised value, and hardware that only supports 32-bit writes will ignore the high 32-bit write. Previous xHCI code represented 64-bit addresses with two u32 values. This lead to buggy code that would write the 32-bits in the wrong order, or forget to write the upper 32-bits. Change the two u32s to one u64 and create a function call to write all 64-bit addresses in the proper order. This new function could be modified in the future if all platforms support 64-bit writes. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Deal with stalled endpoints.Sarah Sharp
When an endpoint on a device under an xHCI host controller stalls, the host controller driver must let the hardware know that the USB core has successfully cleared the halt condition. The HCD submits a Reset Endpoint Command, which will clear the toggle bit for USB 2.0 devices, and set the sequence number to zero for USB 3.0 devices. The xHCI urb_enqueue will accept new URBs while the endpoint is halted, and will queue them to the hardware rings. However, the endpoint doorbell will not be rung until the Reset Endpoint Command completes. Don't queue a reset endpoint command for root hubs. khubd clears halt conditions on the roothub during the initialization process, but the roothub isn't a real device, so the xHCI host controller doesn't need to know about the cleared halt. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28USB: xhci: Set TD size in transfer TRB.Sarah Sharp
The 0.95 xHCI specification requires software to set the "TD size" field in each transaction request block (TRB). This field gives the host controller an indication of how much data is remaining in the TD (including the buffer in the current TRB). Set this field in bulk TRBs and data stage TRBs for control transfers. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15usb; xhci: Fix TRB offset calculations.Sarah Sharp
Greg KH introduced a bug into xhci_trb_virt_to_dma() when he changed the type of offset to dma_addr_t from unsigned int and dropped the casts to unsigned int around the virtual address pointer subtraction. trb and seg->trbs are both valid pointers to virtual addresses, so the compiler will mod the subtraction by the size of union trb (16 bytes). segment_offset is an unsigned long, which is guaranteed to be at least as big as a void *. Drop the void * casts in the first if statement because trb and seg->trbs are both pointers of the same type (pointers to union trb). Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Avoid compiler reordering in Link TRB giveback.Sarah Sharp
Force the compiler to write the cycle bit of the Link TRB last. This ensures that the hardware doesn't think it owns the Link TRB before we set the chain bit. Reported by Oliver in this thread: http://marc.info/?l=linux-usb&m=124091532410219&w=2 Reported-by: Oliver Neukum <oliver@neukum.org> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Avoid global namespace pollution.Sarah Sharp
Make all globally visible functions start with xhci_ and mark functions as static if they're only called within the same C file. Fix some long lines while we're at it. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Fix Link TRB handoff bit twiddling.Sarah Sharp
Make sure to preserve all bits *except* the TRB_CHAIN bit when giving a Link TRB to the hardware. We need to save things like TRB type and the toggle bit in the control dword. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: fix lots of compiler warnings.Greg Kroah-Hartman
Turns out someone never built this code on a 64bit platform. Someone owes me a beer... Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: use xhci_handle_event instead of handle_eventStephen Rothwell
The former is way to generic for a global symbol. Fixes this build error: drivers/usb/built-in.o: In function `.handle_event': (.text+0x67dd0): multiple definition of `.handle_event' drivers/pcmcia/built-in.o:(.text+0xcfcc): first defined here drivers/usb/built-in.o: In function `handle_event': (.opd+0x5bc8): multiple definition of `handle_event' drivers/pcmcia/built-in.o:(.opd+0xed0): first defined here Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: URB cancellation support.Sarah Sharp
Add URB cancellation support to the xHCI host controller driver. This currently supports cancellation for endpoints that do not have streams enabled. An URB is represented by a number of Transaction Request Buffers (TRBs), that are chained together to make one (or more) Transaction Descriptors (TDs) on an endpoint ring. The ring is comprised of contiguous segments, linked together with Link TRBs (which may or may not be chained into a TD). To cancel an URB, we must stop the endpoint ring, make the hardware skip over the TDs in the URB (either by turning them into No-op TDs, or by moving the hardware's ring dequeue pointer past the last TRB in the last TD), and then restart the ring. There are times when we must drop the xHCI lock during this process, like when we need to complete cancelled URBs. We must ensure that additional URBs can be marked as cancelled, and that new URBs can be enqueued (since the URB completion handlers can do either). The new endpoint ring variables cancels_pending and state (which can only be modified while holding the xHCI lock) ensure that future cancellation and enqueueing do not interrupt any pending cancellation code. To facilitate cancellation, we must keep track of the starting ring segment, first TRB, and last TRB for each URB. We also need to keep track of the list of TDs that have been marked as cancelled, separate from the list of TDs that are queued for this endpoint. The new variables and cancellation list are stored in the xhci_td structure. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Scatter gather list support for bulk transfers.Sarah Sharp
Add support for bulk URBs that pass scatter gather lists to xHCI. This allows xHCI to more efficiently enqueue these transfers, and allows the host controller to take advantage of USB 3.0 "bursts" for bulk endpoints. Use requested length to calculate the number of TRBs needed for a scatter gather list transfer, instead of using the number of sglist entries. The application can pass down a scatter gather list that is bigger than it needs for the requested transfer. Scatter gather entries can cross 64KB boundaries, so be careful to setup TRBs such that no buffer crosses a 64KB boundary. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Bulk transfer supportSarah Sharp
Allow device drivers to submit URBs to bulk endpoints on devices under an xHCI host controller. Share code between the control and bulk enqueueing functions when it makes sense. To get the best performance out of bulk transfers, SuperSpeed devices must have the bMaxBurst size copied from their endpoint companion controller into the xHCI device context. This allows the host controller to "burst" up to 16 packets before it has to wait for the device to acknowledge the first packet. The buffers in Transfer Request Blocks (TRBs) can cross page boundaries, but they cannot cross 64KB boundaries. The buffer must be broken into multiple TRBs if a 64KB boundary is crossed. The sum of buffer lengths in all the TRBs in a Transfer Descriptor (TD) cannot exceed 64MB. To work around this, the enqueueing code must enqueue multiple TDs. The transfer event handler may incorrectly give back the URB in this case, if it gets a transfer event that points somewhere in the first TD. FIXME later. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Bandwidth allocation supportSarah Sharp
Since the xHCI host controller hardware (xHC) has an internal schedule, it needs a better representation of what devices are consuming bandwidth on the bus. Each device is represented by a device context, with data about the device, endpoints, and pointers to each endpoint ring. We need to update the endpoint information for a device context before a new configuration or alternate interface setting is selected. We setup an input device context with modified endpoint information and newly allocated endpoint rings, and then submit a Configure Endpoint Command to the hardware. The host controller can reject the new configuration if it exceeds the bus bandwidth, or the host controller doesn't have enough internal resources for the configuration. If the command fails, we still have the older device context with the previous configuration. If the command succeeds, we free the old endpoint rings. The root hub isn't a real device, so always say yes to any bandwidth changes for it. The USB core will enable, disable, and then enable endpoint 0 several times during the initialization sequence. The device will always have an endpoint ring for endpoint 0 and bandwidth allocated for that, unless the device is disconnected or gets a SetAddress 0 request. So we don't pay attention for when xhci_check_bandwidth() is called for a re-add of endpoint 0. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Control transfer support.Sarah Sharp
Allow device drivers to enqueue URBs to control endpoints on devices under an xHCI host controller. Each control transfer is represented by a series of Transfer Descriptors (TDs) written to an endpoint ring. There is one TD for the Setup phase, (optionally) one TD for the Data phase, and one TD for the Status phase. Enqueue these TDs onto the endpoint ring that represents the control endpoint. The host controller hardware will return an event on the event ring that points to the (DMA) address of one of the TDs on the endpoint ring. If the transfer was successful, the transfer event TRB will have a completion code of success, and it will point to the Status phase TD. Anything else is considered an error. This should work for control endpoints besides the default endpoint, but that hasn't been tested. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Allocate and address USB devicesSarah Sharp
xHCI needs to get a "Slot ID" from the host controller and allocate other data structures for every USB device. Make usb_alloc_dev() and usb_release_dev() allocate and free these device structures. After setting up the xHC device structures, usb_alloc_dev() must wait for the hardware to respond to an Enable Slot command. usb_alloc_dev() fires off a Disable Slot command and does not wait for it to complete. When the USB core wants to choose an address for the device, the xHCI driver must issue a Set Address command and wait for an event for that command. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: Root hub support.Sarah Sharp
Add functionality for getting port status and hub descriptor for xHCI root hubs. This is WIP because the USB 3.0 hub descriptor is different from the USB 2.0 hub descriptor. For now, we lie about the root hub descriptor because the changes won't effect how the core talks to the root hub. Later we will need to add the USB 3.0 hub descriptor for real hubs, and this code might change. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: xhci: No-op command queueing and irq handler.Sarah Sharp
xHCI host controllers can optionally implement a no-op test. This simple test ensures the OS has correctly setup all basic data structures and can correctly respond to interrupts from the host controller hardware. There are two rings exercised by the no-op test: the command ring, and the event ring. The host controller driver writes a no-op command TRB to the command ring, and rings the doorbell for the command ring (the first entry in the doorbell array). The hardware receives this event, places a command completion event on the event ring, and fires an interrupt. The host controller driver sees the interrupt, and checks the event ring for TRBs it can process, and sees the command completion event. (See the rules in xhci-ring.c for who "owns" a TRB. This is a simplified set of rules, and may not contain all the details that are in the xHCI 0.95 spec.) A timer fires every 60 seconds to debug the state of the hardware and command and event rings. This timer only runs if CONFIG_USB_XHCI_HCD_DEBUGGING is 'y'. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>