| Message ID | 20210511101522.34193-1-chunfeng.yun@mediatek.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: core: hub: fix race condition about TRSMRCY of resume | expand |
On Tue, May 11, 2021 at 06:15:22PM +0800, Chunfeng Yun wrote: > This may happen if the port becomes resume status exactly > when usb_port_resume() gets port status, it still need provide > a TRSMCRY time before access the device. > > Reported-by: Tianping Fang <tianping.fang@mediatek.com> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> > --- > drivers/usb/core/hub.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) Does this need to go to any older/stable kernels? If so, how far back? thanks, greg k-h
On Tue, 2021-05-11 at 13:27 +0200, Greg Kroah-Hartman wrote: > On Tue, May 11, 2021 at 06:15:22PM +0800, Chunfeng Yun wrote: > > This may happen if the port becomes resume status exactly > > when usb_port_resume() gets port status, it still need provide > > a TRSMCRY time before access the device. > > > > Reported-by: Tianping Fang <tianping.fang@mediatek.com> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> > > --- > > drivers/usb/core/hub.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > Does this need to go to any older/stable kernels? If so, how far back? The flow is changed by "b01b03f3ad82 USB: add new routine for checking port-resume type", but it will cause conflict with "ad493e5e5805 usb: add usb port auto power off mechanism" > > thanks, > > greg k-h
On Tue, 2021-05-11 at 12:39 -0400, Alan Stern wrote: > On Tue, May 11, 2021 at 06:15:22PM +0800, Chunfeng Yun wrote: > > This may happen if the port becomes resume status exactly > > when usb_port_resume() gets port status, it still need provide > > a TRSMCRY time before access the device. > > > > Reported-by: Tianping Fang <tianping.fang@mediatek.com> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> > > This should also say: > > CC: <stable@vger.kernel.org> OK, thanks > > > --- > > drivers/usb/core/hub.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > > index b2bc4b7c4289..fc7d6cdacf16 100644 > > --- a/drivers/usb/core/hub.c > > +++ b/drivers/usb/core/hub.c > > @@ -3642,9 +3642,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) > > * sequence. > > */ > > status = hub_port_status(hub, port1, &portstatus, &portchange); > > - > > - /* TRSMRCY = 10 msec */ > > - msleep(10); > > } > > > > SuspendCleared: > > @@ -3659,6 +3656,9 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) > > usb_clear_port_feature(hub->hdev, port1, > > USB_PORT_FEAT_C_SUSPEND); > > } > > + > > + /* TRSMRCY = 10 msec */ > > + msleep(10); > > } > > > > if (udev->persist_enabled) > > Acked-by: Alan Stern <stern@rowland.harvard.edu>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index b2bc4b7c4289..fc7d6cdacf16 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3642,9 +3642,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) * sequence. */ status = hub_port_status(hub, port1, &portstatus, &portchange); - - /* TRSMRCY = 10 msec */ - msleep(10); } SuspendCleared: @@ -3659,6 +3656,9 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) usb_clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_SUSPEND); } + + /* TRSMRCY = 10 msec */ + msleep(10); } if (udev->persist_enabled)
This may happen if the port becomes resume status exactly when usb_port_resume() gets port status, it still need provide a TRSMCRY time before access the device. Reported-by: Tianping Fang <tianping.fang@mediatek.com> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> --- drivers/usb/core/hub.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)