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

[Chauhan, Madhav]

> -----Original Message-----
> From: Ander Conselvan De Oliveira [mailto:conselvan2 at gmail.com]
> Sent: Friday, April 28, 2017 2:28 PM
> To: Chauhan, Madhav <madhav.chauhan at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Deepak M <m.deepak 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: Re: [PATCH] drm/i915/glk: Fix DSI "*ERROR* ULPS is still active"
> messages
> 
> 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>

Reviewed-by: Madhav Chauhan <madhav.chauhan 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
> >
> >