Re: [PATCH] Input: fix Cypress PS/2 Trackpad in Dell XPS12

[Kamal Mostafa]

On Thu, 2013-02-21 at 11:56 -0800, Dmitry Torokhov wrote:
> On Thu, Feb 21, 2013 at 10:55:55AM -0800, Kamal Mostafa wrote:
> > Avoid firmware glitch in Cypress PS/2 Trackpad firmware version 11
> > (as observed in Dell XPS12) which prevents driver from recognizing
> > the trackpad.
> > 
> > BugLink: http://launchpad.net/bugs/1103594
> > 
> > Signed-off-by: Kamal Mostafa <ka...@canonical.com>
> > Cc: Dudley Du <d...@cypress.com>
> > ---
> >  drivers/input/mouse/cypress_ps2.c |   19 +++++++++++++------
> >  1 file changed, 13 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/input/mouse/cypress_ps2.c 
> > b/drivers/input/mouse/cypress_ps2.c
> > index 1673dc6..f51765f 100644
> > --- a/drivers/input/mouse/cypress_ps2.c
> > +++ b/drivers/input/mouse/cypress_ps2.c
> > @@ -236,6 +236,13 @@ static int cypress_read_fw_version(struct psmouse 
> > *psmouse)
> >     cytp->fw_version = param[2] & FW_VERSION_MASX;
> >     cytp->tp_metrics_supported = (param[2] & TP_METRICS_MASK) ? 1 : 0;
> >  
> > +   /*
> > +    * Trackpad fw_version 11 (in Dell XPS12) yields a bogus response to
> > +    * CYTP_CMD_READ_TP_METRICS so do not try to use it. LP: #1103594.
> > +    */
> > +   if (cytp->fw_version >= 11)
> > +           cytp->tp_metrics_supported = 0;
> > +
> 
> Isn't this the only chunk that is actually needed to fix the issue?

No, the other parts are needed also:  The handling of
tp_metrics_supported gets moved so that the default values now get set
first, then overridden only if tp_metrics_supported is true.
Previously, the defaults wouldn't get set if it wasn't true (which was a
bug that never manifested).

 -Kamal


> Thanks.
> 
> >     psmouse_dbg(psmouse, "cytp->fw_version = %d\n", cytp->fw_version);
> >     psmouse_dbg(psmouse, "cytp->tp_metrics_supported = %d\n",
> >              cytp->tp_metrics_supported);
> > @@ -258,6 +265,9 @@ static int cypress_read_tp_metrics(struct psmouse 
> > *psmouse)
> >     cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
> >     cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
> >  
> > +   if (!cytp->tp_metrics_supported)
> > +           return 0;
> > +
> >     memset(param, 0, sizeof(param));
> >     if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_TP_METRICS, param) == 
> > 0) {
> >             /* Update trackpad parameters. */
> > @@ -315,18 +325,15 @@ static int cypress_read_tp_metrics(struct psmouse 
> > *psmouse)
> >  
> >  static int cypress_query_hardware(struct psmouse *psmouse)
> >  {
> > -   struct cytp_data *cytp = psmouse->private;
> >     int ret;
> >  
> >     ret = cypress_read_fw_version(psmouse);
> >     if (ret)
> >             return ret;
> >  
> > -   if (cytp->tp_metrics_supported) {
> > -           ret = cypress_read_tp_metrics(psmouse);
> > -           if (ret)
> > -                   return ret;
> > -   }
> > +   ret = cypress_read_tp_metrics(psmouse);
> > +   if (ret)
> > +           return ret;
> >  
> >     return 0;
> >  }
> > -- 
> > 1.7.10.4
> > 
> 

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