Re: [PATCH] xhci: EHCI/xHCI ports switching on Intense-PC.

From: Denis Turischev
Date: Wed Jul 18 2012 - 02:57:32 EST


On 07/17/2012 07:54 AM, Sarah Sharp wrote:
> On Mon, Jul 16, 2012 at 07:46:06PM +0300, Denis Turischev wrote:
>> Intense-PC is Compulab's mini-desktop with Intel Panther Point
>> chipset.
>>
>> Unconditional ports switching provided by function
>> usb_enable_xhci_ports() leads to surprising results, after shutdown
>> system powered-on again after a few seconds. On Windows power
>> related problems were not observed.
>
> Do you have wake on lan enabled in the BIOS? I have heard reports from
> other users that this is a BIOS bug triggered by WOL.

Bug appears with WOL disabled too, moreover, it appears with PCH LAN
disabled at all in the BIOS.

>
>> The patch avoids ports switching for Intense-PC.
>>
>> Signed-off-by: Denis Turischev <denis@xxxxxxxxxxxxxx>
>> ---
>> drivers/usb/host/pci-quirks.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
>> index df0828c..6f72593 100644
>> --- a/drivers/usb/host/pci-quirks.c
>> +++ b/drivers/usb/host/pci-quirks.c
>> @@ -759,6 +759,13 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
>> {
>> u32 ports_available;
>>
>> + const char *brd_name;
>> + brd_name = dmi_get_system_info(DMI_BOARD_NAME);
>> +
>> + /* quirk for Compulab's Intense-PC board */
>> + if (brd_name && strstr(brd_name, "Intense-PC"))
>> + return;
>> +
>
> No, this fix is not acceptable. You won't get USB 3.0 speeds if the
> ports are not switched over. Now, we can add a quirk to the xHCI
> shutdown function to switch the ports back to EHCI on shutdown. That
> might not trigger the BIOS bug.

Yes, switching back to EHCI in xhci_shutdown() solves the problem.

I suppose to do something like this in xhci_shutdown:
pdev = to_pci_dev(hcd->self.controller);

if (usb_is_intel_switchable_xhci(pdev)){
brd_name = dmi_get_system_info(DMI_BOARD_NAME);

/* quirk for Compulab's Intense-PC board */
if (brd_name && strstr(brd_name, "Intense-PC"))
usb_disable_xhci_ports(pdev);
}

Is it ok?

May be it worth to disable xhci ports for all intel switchable
devices, not only for Intense-PC?

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