diff options
| author | david-b@pacbell.net <david-b@pacbell.net> | 2005-08-13 18:41:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-09-08 16:28:35 -0700 |
| commit | e09711aef4180002241c7f2eab37390ddf40d6a0 (patch) | |
| tree | 9a537e417df8b8ab0d8e121f6a3e596898ec8ec0 /drivers/usb/core/hub.c | |
| parent | 090ffa9d0e904e1ed0f86c84dcf20684a8ac1a5a (diff) | |
[PATCH] ehci: add think_time
This adds think_time to the usb_tt struct and sets it appropriately
(measured in ns); this can help us implement better split transaction
scheduling.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core/hub.c')
| -rw-r--r-- | drivers/usb/core/hub.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 9f54e8330f7..758c7f0ed15 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -627,19 +627,33 @@ static int hub_configure(struct usb_hub *hub, break; } + /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */ switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_TTTT) { - case 0x00: - if (hdev->descriptor.bDeviceProtocol != 0) - dev_dbg(hub_dev, "TT requires at most 8 FS bit times\n"); + case HUB_TTTT_8_BITS: + if (hdev->descriptor.bDeviceProtocol != 0) { + hub->tt.think_time = 666; + dev_dbg(hub_dev, "TT requires at most %d " + "FS bit times (%d ns)\n", + 8, hub->tt.think_time); + } break; - case 0x20: - dev_dbg(hub_dev, "TT requires at most 16 FS bit times\n"); + case HUB_TTTT_16_BITS: + hub->tt.think_time = 666 * 2; + dev_dbg(hub_dev, "TT requires at most %d " + "FS bit times (%d ns)\n", + 16, hub->tt.think_time); break; - case 0x40: - dev_dbg(hub_dev, "TT requires at most 24 FS bit times\n"); + case HUB_TTTT_24_BITS: + hub->tt.think_time = 666 * 3; + dev_dbg(hub_dev, "TT requires at most %d " + "FS bit times (%d ns)\n", + 24, hub->tt.think_time); break; - case 0x60: - dev_dbg(hub_dev, "TT requires at most 32 FS bit times\n"); + case HUB_TTTT_32_BITS: + hub->tt.think_time = 666 * 4; + dev_dbg(hub_dev, "TT requires at most %d " + "FS bit times (%d ns)\n", + 32, hub->tt.think_time); break; } |