Re: [PATCH] Reset ps/2 port should psmouse_probe fail before retrying

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Thursday 22 April 2010 05:47:48 pm Christoph Fritz wrote:
> Am Donnerstag, den 22.04.2010, 14:55 -0700 schrieb Dmitry Torokhov:
> > On Thu, Apr 22, 2010 at 05:48:21PM -0400, Peter M. Petrakis wrote:
> > > Hi,
> > > 
> > > This one is a winner. with regards to your follow up. I wouldn't
> > > want to reset something unless we have cause to. This code
> > > seems to be doing the right thing e.g. I see "unable to query
> > > synaptics hardware" followed by it's (re)discovery on return
> > > from S3.
> > > 
> > > When it's fully supported by the Synaptics driver, the initial
> > > reconnect will succeed and we'll never get to this additional
> > > failsafe code which is essentially a catch all for the bleeding
> > > edge.
> > 
> > I am confused here... what protocol does the kernel select upon fresh
> > boot?
> 
> Peter's dmesg:
> 
> [    7.428561] Unable to query Synaptics hardware.
> 
>  It's plain PS/2 or IMPS/2 because this bleeding edge device fails
> somewehre in synaptics_query_hardware(). Most likely the test on
> priv->identity.

Ah, I missed that. Peter, could you boot with i8042.debug so we could see 
where exactly Synaptics detection fails?

> 
> [    8.239494] input: PS/2 Synaptics TouchPad as
> /devices/platform/i8042/serio1/input/input12
> 
> This is the normal KERN_INFO printk of input_register_device() which does
> not mean that it's using the synaptics driver. "PS/2 Synaptics TouchPad"
> is just the name of the device.
> 
> in conclusion:
>  If a Synaptics touchpad can't be initialized (synaptics_init) and falls
> back to PS/2, it doesn't get a psmouse_reset() after resuming from
> suspend as it would get with a synaptics driver.

Yes, you are right. Maybe we should just reset psmouse unconditionally in 
psmouse_reconnect() before actually doing any protocol reconnect/reprobe. That 
should help in cases when users not enable Synaptics support; also it is 
probably unlikely that mouse that was there gets unplugged after resume.

-- 
Dmitry