Re: [PATCH] drm/i915: Use dpcd read wake for sink crc calls.

Vivi, Rodrigo
2015-08-24T21:20:34Z

On Mon, 2015-08-24 at 19:54 +0000, Zanoni, Paulo R wrote:
> Em Qui, 2015-08-20 às 16:23 -0700, Rodrigo Vivi escreveu:
> > Let's use a native read with retry as suggested per spec to
> > fix Sink CRC on SKL when PSR is enabled.
> >
> > With PSR enabled panel is probably taking more time to wake
> > and dpcd read is faling.
>
> Does this commit actually fix any known problem with Sink CRC? Or is
> it
> just a try? It would be nice to have this clarified in the commit
> message.

It was just a try but that made sink crc working on my SKL when PSR is
enabled. nothing much to add...

>
> Anyway, it looks correct, so:
> Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
>
> >
> > v2: Fix my email domain on commit message. Thanks Rafael.
> >
> > Cc: Rafael Antognolli <rafael.antognolli@intel.com>
> > Cc: Sonika Jindal <sonika.jindal@intel.com>
> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > ---
> > drivers/gpu/drm/i915/intel_dp.c | 15 +++++++++------
> > 1 file changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index d32ce48..34f5e33 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -4037,7 +4037,8 @@ static int intel_dp_sink_crc_stop(struct
> > intel_dp *intel_dp)
> > u8 buf;
> > int ret = 0;
> >
> > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf)
> > <
> > 0) {
> > + if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_TEST_SINK,
> > + &buf, 1) < 0) {
> > DRM_DEBUG_KMS("Sink CRC couldn't be stopped
> > properly\n");
> > ret = -EIO;
> > goto out;
> > @@ -4069,7 +4070,8 @@ static int intel_dp_sink_crc_start(struct
> > intel_dp *intel_dp)
> > return ret;
> > }
> >
> > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC,
> > &buf) < 0)
> > + if (intel_dp_dpcd_read_wake(&intel_dp->aux,
> > DP_TEST_SINK_MISC,
> > + &buf, 1) < 0)
> > return -EIO;
> >
> > if (!(buf & DP_TEST_CRC_SUPPORTED))
> > @@ -4077,7 +4079,7 @@ static int intel_dp_sink_crc_start(struct
> > intel_dp *intel_dp)
> >
> > intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK;
> >
> > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf)
> > <
> > 0)
> > + if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_TEST_SINK,
> > &buf, 1) < 0)
> > return -EIO;
> >
> > hsw_disable_ips(intel_crtc);
> > @@ -4109,8 +4111,8 @@ int intel_dp_sink_crc(struct intel_dp
> > *intel_dp, u8 *crc)
> > do {
> > intel_wait_for_vblank(dev, intel_crtc->pipe);
> >
> > - if (drm_dp_dpcd_readb(&intel_dp->aux,
> > - DP_TEST_SINK_MISC, &buf) <
> > 0)
> > {
> > + if (intel_dp_dpcd_read_wake(&intel_dp->aux,
> > + DP_TEST_SINK_MISC,
> > &buf,
> > 1) < 0) {
> > ret = -EIO;
> > goto stop;
> > }
> > @@ -4123,7 +4125,8 @@ int intel_dp_sink_crc(struct intel_dp
> > *intel_dp, u8 *crc)
> > if (count == 0)
> > intel_dp->sink_crc.last_count = 0;
> >
> > - if (drm_dp_dpcd_read(&intel_dp->aux,
> > DP_TEST_CRC_R_CR, crc, 6) < 0) {
> > + if (intel_dp_dpcd_read_wake(&intel_dp->aux,
> > DP_TEST_CRC_R_CR,
> > + crc, 6) < 0) {
> > ret = -EIO;
> > goto stop;