[Intel-gfx] [PATCH] drm/i915/glk: Fix DSI "*ERROR* ULPS is still active" messages

[Ander Conselvan De Oliveira]

On Fri, 2017-04-28 at 08:50 +0000, Chauhan, Madhav wrote:
> > -----Original Message-----
> > From: Conselvan De Oliveira, Ander
> > Sent: Friday, April 28, 2017 1:32 PM
> > To: intel-gfx at lists.freedesktop.org
> > Cc: Conselvan De Oliveira, Ander <ander.conselvan.de.oliveira at intel.com>;
> > Deepak M <m.deepak at intel.com>; Chauhan, Madhav
> > <madhav.chauhan at intel.com>; Nikula, Jani <jani.nikula at intel.com>; Vetter,
> > Daniel <daniel.vetter at intel.com>; Jani Nikula <jani.nikula at linux.intel.com>;
> > drm-intel-fixes at lists.freedesktop.org
> > Subject: [PATCH] drm/i915/glk: Fix DSI "*ERROR* ULPS is still active"
> > messages
> > 
> > The sequence in glk_dsi_device_ready() enters ULPS then waits until it is
> > *not* active to then disable it. The correct sequence according to the spec is
> > to enter ULPS then wait until the GLK_ULPS_NOT_ACTIVE bit is zero, i.e., ULPS
> > is active, and then disable ULPS.
> > 
> > Fixing the codition gets rid of the following spurious error messages:
> 
> Please correct the typo error to "condition", otherwise looks good.
> Thanks for catching this.

If you upgrade the above statement to a Reviewed-by, I can fix the typo while
merging?

Ander

> 
> > 
> > [drm:glk_dsi_device_ready [i915]] *ERROR* ULPS is still active
> > 
> > Fixes: 4644848369c0 ("drm/i915/glk: Add MIPIIO Enable/disable sequence")
> > Cc: Deepak M <m.deepak at intel.com>
> > Cc: Madhav Chauhan <madhav.chauhan at intel.com>
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Daniel Vetter <daniel.vetter at intel.com>
> > Cc: Jani Nikula <jani.nikula at linux.intel.com>
> > Cc: intel-gfx at lists.freedesktop.org
> > Cc: <drm-intel-fixes at lists.freedesktop.org>
> > Signed-off-by: Ander Conselvan de Oliveira
> > <ander.conselvan.de.oliveira at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_dsi.c | 7 +++----
> >  1 file changed, 3 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dsi.c
> > b/drivers/gpu/drm/i915/intel_dsi.c
> > index 3ffe8b1..fc0ef49 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi.c
> > +++ b/drivers/gpu/drm/i915/intel_dsi.c
> > @@ -410,11 +410,10 @@ static void glk_dsi_device_ready(struct
> > intel_encoder *encoder)
> >  		val |= (ULPS_STATE_ENTER | DEVICE_READY);
> >  		I915_WRITE(MIPI_DEVICE_READY(port), val);
> > 
> > -		/* Wait for ULPS Not active */
> > +		/* Wait for ULPS active */
> >  		if (intel_wait_for_register(dev_priv,
> > -				MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE,
> > -				GLK_ULPS_NOT_ACTIVE, 20))
> > -			DRM_ERROR("ULPS is still active\n");
> > +				MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE, 0,
> > 20))
> > +			DRM_ERROR("ULPS not active\n");
> > 
> >  		/* Exit ULPS */
> >  		val = I915_READ(MIPI_DEVICE_READY(port));
> > --
> > 2.9.3
> 
>