| Message ID | 20210511002933.1612871-1-luzmaximilian@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: xhci: Increase timeout for HC halt | expand |
On Tue, May 11, 2021 at 02:29:33AM +0200, Maximilian Luz wrote: > On some devices (specifically the SC8180x based Surface Pro X with > QCOM04A6) HC halt / xhci_halt() times out during boot. Manually binding > the xhci-hcd driver at some point later does not exhibit this behavior. > To work around this, double XHCI_MAX_HALT_USEC, which also resolves this > issue. > > Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> > --- > drivers/usb/host/xhci-ext-caps.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Should this go to stable kernels as well? thanks, greg k-h
On 5/11/21 9:19 AM, Mathias Nyman wrote: > On 11.5.2021 3.29, Maximilian Luz wrote: >> On some devices (specifically the SC8180x based Surface Pro X with >> QCOM04A6) HC halt / xhci_halt() times out during boot. Manually binding >> the xhci-hcd driver at some point later does not exhibit this behavior. >> To work around this, double XHCI_MAX_HALT_USEC, which also resolves this >> issue. >> >> Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> >> --- >> drivers/usb/host/xhci-ext-caps.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h >> index fa59b242cd51..fb591e41cd50 100644 >> --- a/drivers/usb/host/xhci-ext-caps.h >> +++ b/drivers/usb/host/xhci-ext-caps.h >> @@ -7,8 +7,8 @@ >> * Author: Sarah Sharp >> * Some code borrowed from the Linux EHCI driver. >> */ >> -/* Up to 16 ms to halt an HC */ >> -#define XHCI_MAX_HALT_USEC (16*1000) >> +/* Up to 32 ms to halt an HC */ >> +#define XHCI_MAX_HALT_USEC (32 * 1000) > > xHCI spec has a 16ms limit stated in several places, for example section 5.4.1 > "xHC is forced to halt within 16 ms. of software clearing the R/S bit to ‘0’, > irrespective of any queued Transfer or Command Ring activity" Right, thanks, I wasn't aware of this. > To make sure hosts work we could increase it to 32, but comment could be > changed to make sure it doean't get optimized back to 16 ms later. > > How about: > /* HC should halt within 16 ms, but use 32 ms as some in reality take longer */ > > If that's ok I can take this and modify the comment That makes sense, yes. Please feel free to change that comment as you wish. Regards, Max
diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h index fa59b242cd51..fb591e41cd50 100644 --- a/drivers/usb/host/xhci-ext-caps.h +++ b/drivers/usb/host/xhci-ext-caps.h @@ -7,8 +7,8 @@ * Author: Sarah Sharp * Some code borrowed from the Linux EHCI driver. */ -/* Up to 16 ms to halt an HC */ -#define XHCI_MAX_HALT_USEC (16*1000) +/* Up to 32 ms to halt an HC */ +#define XHCI_MAX_HALT_USEC (32 * 1000) /* HC not running - set to 1 when run/stop bit is cleared. */ #define XHCI_STS_HALT (1<<0)
On some devices (specifically the SC8180x based Surface Pro X with QCOM04A6) HC halt / xhci_halt() times out during boot. Manually binding the xhci-hcd driver at some point later does not exhibit this behavior. To work around this, double XHCI_MAX_HALT_USEC, which also resolves this issue. Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> --- drivers/usb/host/xhci-ext-caps.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)