Re: [PATCH] serio: delay resume error handling til PM complete

[Todd E Brandt <todd.e.brandt@linux.intel.com>]

On Wed, Nov 25, 2015 at 09:51:12AM -0800, Dmitry Torokhov wrote:
> On Wed, Nov 25, 2015 at 09:25:59AM -0800, Todd E Brandt wrote:
> > On Tue, Nov 24, 2015 at 05:26:15PM -0800, Dmitry Torokhov wrote:
> > > On Tue, Nov 24, 2015 at 4:58 PM, Todd Brandt
> > > <todd.e.brandt@linux.intel.com> wrote:
> > > >  Delay the error rescan for serio devices until the PM
> > > >  complete phase. PM complete requires locking each device
> > > >  before checking for and executing the complete callbacks.
> > > >  Serio rescan also locks the device in order to reinit on
> > > >  error, so this can cause a conflict which will result in
> > > >  unnecessary delay.
> > > >
> > > >  History:
> > > >
> > > >  The issue was discovered on an ivy bridge platform with
> > > >  i8042 keyboard/mouse. The mouse resume fails
> > > 
> > > I'd first try to figure out why reconnect failed. What kind of
> > > mouse/touchpad is that?
> > 
> > It's an Alps PS/2 glidepoint touchpad. The actual error appears to be
> > a failure in alps_identify as it attempts to get the EC report using
> > alps_rpt_cmd. However, I don't think this is too important since
> > the psmouse driver is just doing what it's supposed to. It's the
> > fact that the error was mitigated right in the middle of the system
> > resume that caused the delay.
> > 
> > I expect that errors in input drivers will happen quite a lot. Users
> 
> I do not expect that. If device is still there then we should be able to
> communicate with it. Failure to do so indicates that there is some issue
> (resume order?) and I would like to know what it is.

OK, I'll track it down. It's an off the shelf laptop so I don't expect
it's a hardware issue.

> 
> >
> > don't typically care as long as the device eventually rights itself
> > and they don't notice. 
> 
> Theoretically you lose settings that you done manually through sysfs.
> Suspend/resume cycle is not supposed to lose your settings.

Agreed, but I think in most cases errors like these would go unnoticed.
But I understand your point.

> 
> Thanks.
> 
> -- 
> Dmitry
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html