Hi John, On 19 January 2017 at 09:33, John Youn <John.Youn@xxxxxxxxxxxx> wrote: > On 1/16/2017 2:38 AM, Felipe Balbi wrote: >> >> Hi, >> >> John Youn <John.Youn@xxxxxxxxxxxx> writes: >>>> Baolin Wang <baolin.wang@xxxxxxxxxx> writes: >>>>>> Baolin Wang <baolin.wang@xxxxxxxxxx> 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.wang@xxxxxxxxxx> >>>>>>> --- >>>>>>> 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. >> > > Hi Felipe, Baolin, > > I talked with a couple engineers here and the behavior is not > something that's expected in host mode. > > Can you check that the value of the GCTL.RAMCLKSEL is set > appropriately? This affects where the core gets the clock signal In host mode, the bit[6:7] for RAMCLKSEL is default value 0, which means it selects bus clock. > from. If it is getting it from the phy clock then you will likely have > this problem and will need to adjust it. Otherwise you should probably > use the existing quirk instead. So the bus clock is from the phy clock, then it will have this problem when suspending phy? Yes, I can use the existing quirk, but I am afraid it is one common problem if we use the mainline kernel. Or we can add some documentation for enabling the phy suspend feature to remind other people. -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
