On Fri, Nov 05, 2021 at 11:00:31AM +0100, Greg Kroah-Hartman wrote: > On Wed, Nov 03, 2021 at 10:37:33PM +0200, Mathias Nyman wrote: > > On 2.11.2021 22.29, Walt Jr. Brake wrote: > > > On 2/11/2021 17:05, Mathias Nyman wrote: > > >> On 1.11.2021 16.06, Alan Stern wrote: > > >>> On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote: > > >>>> This patch make USB 3.1 device cannot be detected, and I report the bug [1] > > >>>> to archlinux three month ago. Yesterday I try to fix it myself, and after I > > >>>> revert this patch, compile the kernel and test, it works. > > >>>> > > >>>> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2 > > >>>> > > >>>> > > >>>> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h > > >>>> index 22ea1f4f2d66..73f4482d833a 100644 > > >>>> --- a/drivers/usb/core/hub.h > > >>>> +++ b/drivers/usb/core/hub.h > > >>>> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct > > >>>> usb_hub *hub) > > >>>> { > > >>>> unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2; > > >>>> > > >>>> - if (!hub->hdev->parent) /* root hub */ > > >>>> - return delay; > > >>>> - else /* Wait at least 100 msec for power to become stable */ > > >>>> - return max(delay, 100U); > > >>>> + /* Wait at least 100 msec for power to become stable */ > > >>>> + return max(delay, 100U); > > >>>> } > > >>> Mathias: > > >>> > > >>> It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is > > >>> too small for some USB 3.1 devices. > > >>> > > >>> Can you look into this? > > >>> > > >>> Alan Stern > > >>> > > >> At first glance the xhci roothub bPwrOn2PwrGood value looks ok. > > >> xhci spec 5.4.8 states software should wait 20ms after asserting PP, before > > >> attempting to change the state of the port. > > >> > > >> xhci driver sets desc->bPwrOn2PwrGood = 10; (2ms interval, so equals 20ms ) > > >> > > >> We should probably get this working immediately, so maybe revert that patch > > >> while looking into the rootcause. > > >> > > >> Walt Jr. Brake, instead of reverting that patch, could you test if changing the > > >> xhci roothub bPwrOn2PwrGood value helps. > > >> > > >> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c > > >> index a3f875eea751..756231a55602 100644 > > >> --- a/drivers/usb/host/xhci-hub.c > > >> +++ b/drivers/usb/host/xhci-hub.c > > >> @@ -257,7 +257,7 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci, > > >> { > > >> u16 temp; > > >> - desc->bPwrOn2PwrGood = 10; /* xhci section 5.4.9 says 20ms max */ > > >> + desc->bPwrOn2PwrGood = 50; /* The 20ms in xhci 5.4.8 isn't enough for USB 3.1 */ > > >> desc->bHubContrCurrent = 0; > > >> desc->bNbrPorts = ports; > > >> > > >> Thanks > > >> -Mathias > > > > > > Mathias: > > > > > > Sorry to reply lately. I test with your patch, it works. > > > > > > I also test with setting bPwrOn2PwrGood to 45, and it not work. > > > > > > Seems that the minimal value should be 50 for this case. > > > > > > > Thanks for testing, and for checking that 90ms wait isn't enough > > Can you send a "real" patch for this so I can get it into the tree soon > to resolve the regression? Also, it might make sense to move the desc->bPwrOn2PwrGood setting from xhci_common_hub_descriptor into the speed-specific routines. For the USB-2 root hub the value can remain set to 10; only the USB-3 root hub needs to be changed. Alan Stern
