Messages in this thread Patch in this message | | | Date | Fri, 16 Mar 2007 09:34:29 -0400 (EDT) | From | Alan Stern <> | Subject | [PATCH] EHCI: add delay to bus_resume before accessing ports |
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This patch (as870) adds a delay to ehci-hcd's bus_resume routine. Apparently there are controllers and/or BIOSes out there which need such a delay to get the ports back into their correct state. This fixes Bugzilla #8190.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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This is for 2.6.20-stable. Earlier kernels aren't so eager to suspend EHCI buses and so don't need this fix.
Index: 2.6.20/drivers/usb/host/ehci-hub.c =================================================================== --- 2.6.20.orig/drivers/usb/host/ehci-hub.c +++ 2.6.20/drivers/usb/host/ehci-hub.c @@ -134,6 +134,10 @@ static int ehci_bus_resume (struct usb_h /* restore CMD_RUN, framelist size, and irq threshold */ writel (ehci->command, &ehci->regs->command); + /* Some controller/firmware combinations need a delay during which + * they set up the port statuses. See Bugzilla #8190. */ + mdelay(8); + /* manually resume the ports we suspended during bus_suspend() */ i = HCS_N_PORTS (ehci->hcs_params); while (i--) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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