On 1/11/2017 11:51 PM, Felipe Balbi wrote: > > Hi, > > Baolin Wang <baolin.w...@linaro.org> writes: >>> Baolin Wang <baolin.w...@linaro.org> writes: >>>> When dwc3 controller acts as host role with attaching slow speed device >>>> (like mouse or keypad). Then if we plugged out the slow speed device, >>>> it will timeout to run the deconfiguration endpoint command to drop the >>>> endpoint's resources. Some xHCI command timeout log as below when >>>> disconnecting one slow device: >>>> >>>> [ 99.807739] c0 xhci-hcd.0.auto: Port Status Change Event for port 1 >>>> [ 99.814699] c0 xhci-hcd.0.auto: resume root hub >>>> [ 99.819992] c0 xhci-hcd.0.auto: handle_port_status: starting port >>>> polling. >>>> [ 99.827808] c0 xhci-hcd.0.auto: get port status, actual port 0 status >>>> = 0x202a0 >>>> [ 99.835903] c0 xhci-hcd.0.auto: Get port status returned 0x10100 >>>> [ 99.850052] c0 xhci-hcd.0.auto: clear port connect change, actual >>>> port 0 status = 0x2a0 >>>> [ 99.859313] c0 xhci-hcd.0.auto: Cancel URB ffffffc01ed6cd00, dev 1, >>>> ep 0x81, starting at offset 0xc406d210 >>>> [ 99.869645] c0 xhci-hcd.0.auto: // Ding dong! >>>> [ 99.874776] c0 xhci-hcd.0.auto: Stopped on Transfer TRB >>>> [ 99.880713] c0 xhci-hcd.0.auto: Removing canceled TD starting at >>>> 0xc406d210 (dma). >>>> [ 99.889012] c0 xhci-hcd.0.auto: Finding endpoint context >>>> [ 99.895069] c0 xhci-hcd.0.auto: Cycle state = 0x1 >>>> [ 99.900519] c0 xhci-hcd.0.auto: New dequeue segment = >>>> ffffffc1112f0880 (virtual) >>>> [ 99.908655] c0 xhci-hcd.0.auto: New dequeue pointer = 0xc406d220 (DMA) >>>> [ 99.915927] c0 xhci-hcd.0.auto: Set TR Deq Ptr cmd, new deq seg = >>>> ffffffc1112f0880 (0xc406d000 dma), >>>> new deq ptr = ffffff8002175220 >>>> (0xc406d220 dma), new cycle = 1 >>>> [ 99.931242] c0 xhci-hcd.0.auto: // Ding dong! >>>> [ 99.936360] c0 xhci-hcd.0.auto: Successful Set TR Deq Ptr cmd, >>>> deq = @c406d220 >>>> [ 99.944458] c0 xhci-hcd.0.auto: xhci_hub_status_data: stopping port >>>> polling. >>>> [ 100.047619] c0 xhci-hcd.0.auto: xhci_drop_endpoint called for udev >>>> ffffffc01ae08800 >>>> [ 100.057002] c0 xhci-hcd.0.auto: drop ep 0x81, slot id 1, new drop >>>> flags = 0x8, new add flags = 0x0 >>>> [ 100.067878] c0 xhci-hcd.0.auto: xhci_check_bandwidth called for udev >>>> ffffffc01ae08800 >>>> [ 100.076868] c0 xhci-hcd.0.auto: New Input Control Context: >>>> >>>> ...... >>>> >>>> [ 100.427252] c0 xhci-hcd.0.auto: // Ding dong! >>>> [ 105.430728] c0 xhci-hcd.0.auto: Command timeout >>>> [ 105.436029] c0 xhci-hcd.0.auto: Abort command ring >>>> [ 113.558223] c0 xhci-hcd.0.auto: Command completion event does not match >>>> command >>>> [ 113.569778] c0 xhci-hcd.0.auto: Timeout while waiting for configure >>>> endpoint command >>>> >>>> The reason is it will suspend USB phy to disable phy clock when >>>> disconnecting the slow USB decice, that will hang on the xHCI commands >>>> executing which depends on the phy clock. >>>> >>>> Thus we should disable USB2.0 phy suspend feature when dwc3 acts as host >>>> role. >>>> >>>> Signed-off-by: Baolin Wang <baolin.w...@linaro.org> >>>> --- >>>> drivers/usb/dwc3/core.c | 14 ++++++++++++++ >>>> 1 file changed, 14 insertions(+) >>>> >>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c >>>> index 9a4a5e4..0b646cf 100644 >>>> --- a/drivers/usb/dwc3/core.c >>>> +++ b/drivers/usb/dwc3/core.c >>>> @@ -565,6 +565,20 @@ static int dwc3_phy_setup(struct dwc3 *dwc) >>>> if (dwc->revision > DWC3_REVISION_194A) >>>> reg |= DWC3_GUSB2PHYCFG_SUSPHY; >>>> >>>> + /* >>>> + * When dwc3 controller acts as host role with attaching one slow >>>> speed >>>> + * device (like mouse or keypad). Then if we plugged out the slow >>>> speed >>>> + * device, it will timeout to run the deconfiguration endpoint >>>> command. >>>> + * The reason is it will suspend USB phy to disable phy clock when >>>> + * disconnecting slow speed decice, which will affect the xHCI >>>> commands >>>> + * executing. >>>> + * >>>> + * Thus we should disable USB 2.0 phy suspend feature when dwc3 acts >>>> as >>>> + * host role. >>>> + */ >>>> + if (dwc->dr_mode == USB_DR_MODE_HOST || dwc->dr_mode == >>>> USB_DR_MODE_OTG) >>>> + reg &= ~DWC3_GUSB2PHYCFG_SUSPHY; >>> >>> which version of the core you're using? Recent version (since 1.94A, >> >> My version is 2.80a. >> >>> IIRC) can manage core suspend automatically. Also, this patch of yours >>> will cause a power consumption regression. >> >> Yes, it can manage core suspend automatically, that is the problem. >> When plugging out one mouse or keypad device, the phy will suspend >> automatically to disable the phy clock. But now the disconnecting >> process is not finished, and some xHCI commands (like deconfiguration >> endpoint command to drop endpoint resources) need depend on the phy >> clock, which will hang on the system to timeout the command or abort >> command ring to halt the xHCI. >> >> I agree with you it will cause a power consumption regression, but it >> will cause serious problem if not. Do you have some suggestion? > > sorry for the long delay. This was lost in my inbox. > > I'm not sure this patch is the best solution. There's no mention in > Databook that we should avoid PHY suspend when acting as host. Adding > John here to see if John has any idea of how to fix this. >
I'm not familiar enough with XHCI side of things to say. I'll ask around to see if anyone has an idea. Regards, John -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html