From aab2d4086a1876fcff282aa36e2d4a92aa9935c9 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 Aug 2009 15:39:55 -0500 Subject: USB: ehci-dbgp: errata for EHCI debug controller initialization On some EHCI usb debug controllers, the EHCI debug device will fail to be seen after a port reset, after a warm reset. Two options exist to get the device to initialize correctly. Option 1 is to unplug and plug in the device. Option 2 is to use the EHCI port test to get the usb debug device to start talking again. At that point the debug controller port reset will succeed. Signed-off-by: Jason Wessel Cc: Ingo Molnar Cc: Andrew Morton Cc: Yinghai Lu Cc: "Eric W. Biederman" CC: dbrownell@users.sourceforge.net Signed-off-by: Greg Kroah-Hartman --- drivers/usb/early/ehci-dbgp.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'drivers/usb') diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c index b88cb65b64e..f0a41c647be 100644 --- a/drivers/usb/early/ehci-dbgp.c +++ b/drivers/usb/early/ehci-dbgp.c @@ -478,10 +478,13 @@ int dbgp_external_startup(void) int devnum; struct usb_debug_descriptor dbgp_desc; int ret; - u32 ctrl, portsc; + u32 ctrl, portsc, cmd; int dbg_port = dbgp_phys_port; int tries = 3; + int reset_port_tries = 1; + int try_hard_once = 1; +try_port_reset_again: ret = dbgp_ehci_startup(); if (ret) return ret; @@ -490,6 +493,24 @@ int dbgp_external_startup(void) ret = ehci_wait_for_port(dbg_port); if (ret < 0) { portsc = readl(&ehci_regs->port_status[dbg_port - 1]); + if (!(portsc & PORT_CONNECT) && try_hard_once) { + /* Last ditch effort to try to force enable + * the debug device by using the packet test + * ehci command to try and wake it up. */ + try_hard_once = 0; + cmd = readl(&ehci_regs->command); + cmd &= ~CMD_RUN; + writel(cmd, &ehci_regs->command); + portsc = readl(&ehci_regs->port_status[dbg_port - 1]); + portsc |= PORT_TEST_PKT; + writel(portsc, &ehci_regs->port_status[dbg_port - 1]); + dbgp_ehci_status("Trying to force debug port online"); + mdelay(50); + dbgp_ehci_controller_reset(); + goto try_port_reset_again; + } else if (reset_port_tries--) { + goto try_port_reset_again; + } dbgp_printk("No device found in debug port\n"); return -EIO; } -- cgit v1.2.3