Re: [PATCH 1/2] usb: core: don't try to reset_device() a port that got just disconnected

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Aug 05, 2013 at 09:46:46AM -0700, Sarah Sharp wrote:
> On Mon, Aug 05, 2013 at 01:29:12PM +0800, Greg Kroah-Hartman wrote:
> > On Wed, Jul 31, 2013 at 11:30:28AM -0700, Sarah Sharp wrote:
> > > From: Julius Werner <jwerner@xxxxxxxxxxxx>
> > > 
> > > The USB hub driver's event handler contains a check to catch SuperSpeed
> > > devices that transitioned into the SS.Inactive state and tries to fix
> > > them with a reset. It decides whether to do a plain hub port reset or
> > > call the usb_reset_device() function based on whether there was a device
> > > attached to the port.
> > > 
> > > However, there are device/hub combinations (found with a JetFlash
> > > Transcend mass storage stick (8564:1000) on the root hub of an Intel
> > > LynxPoint PCH) which can transition to the SS.Inactive state on
> > > disconnect (and stay there long enough for the host to notice). In this
> > > case, above-mentioned reset check will call usb_reset_device() on the
> > > stale device data structure. The kernel will send pointless LPM control
> > > messages to the no longer connected device address and can even cause
> > > several 5 second khubd stalls on some (buggy?) host controllers, before
> > > finally accepting the device's fate amongst a flurry of error messages.
> > > 
> > > This patch makes the choice of reset dependent on the port status that
> > > has just been read from the hub in addition to the existence of an
> > > in-kernel data structure for the device, and only proceeds with the more
> > > extensive reset if both are valid.
> > > 
> > > Signed-off-by: Julius Werner <jwerner@xxxxxxxxxxxx>
> > > Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
> > > ---
> > >  drivers/usb/core/hub.c | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > Should this patch also go to the stable kernel releases?
> 
> I wanted to test it for a kernel release to make sure it didn't cause
> any issues before sending it off to stable.  I'm sure it fixes Julius'
> issues on his Intel xHCI host, but I want to make sure it doesn't cause
> issues on other host controllers.

Ok, so you will remember to send it to stable@ after a bit?

In the future, if you want this to "wait" automatically, you can do
something like:
	Cc: stable <stable@xxxxxxxxxxxxxxx> # after 3.12-rc1 is out

or the like, and I'll know to hold off applying it until then.

thanks,

greg k-h
--
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




[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux