[Intel-gfx] [PATCH 2/3] drm/i915/dp: Fix sink-crc reads.
Dhinakaran Pandiyan
dhinakaran.pandiyan at intel.com
Tue Apr 24 21:54:22 UTC 2018
On Tue, 2018-04-24 at 13:55 -0700, Rodrigo Vivi wrote:
> On Mon, Apr 23, 2018 at 07:56:58PM -0700, Dhinakaran Pandiyan wrote:
> > Sink crc is calculated by the sink for static frames irrespective of
> > what the driver sets in TEST_SINK_START dpcd. Since PSR is the only use
> > case for sink crc, we don't really need the sink_crc_{start, stop} code.
> >
> > The second problem with the current implementation is vblank waits.
> > Enabling vblank interrupts triggers PSR exit, which means we aren't
> > really reading the correct CRC values for PSR tests. vblank waits are
> > replaced by delays.
> >
> > With the changes made in this patch, sink CRC is available only for
> > static frames. I have tested this on a SKL laptop with PSR panel.
> >
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_debugfs.c | 2 +-
> > drivers/gpu/drm/i915/intel_dp.c | 114 ++++--------------------------------
> > drivers/gpu/drm/i915/intel_drv.h | 3 +-
> > 3 files changed, 15 insertions(+), 104 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> > index 2f05f5262bba..35fa1418cc07 100644
> > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > @@ -2784,7 +2784,7 @@ static int i915_sink_crc(struct seq_file *m, void *data)
> >
> > intel_dp = enc_to_intel_dp(state->best_encoder);
> >
> > - ret = intel_dp_sink_crc(intel_dp, crtc_state, crc);
> > + ret = intel_dp_sink_crc(intel_dp, crc);
> > if (ret)
> > goto err;
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 7dcc874b7d8f..7352ab631ea8 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -3876,32 +3876,18 @@ intel_dp_configure_mst(struct intel_dp *intel_dp)
> > intel_dp->is_mst);
> > }
> >
> > -static int intel_dp_sink_crc_stop(struct intel_dp *intel_dp,
> > - struct intel_crtc_state *crtc_state, bool disable_wa)
> > +int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
> > {
> > - struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
> > - struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> > - struct intel_crtc *intel_crtc = to_intel_crtc(crtc_state->base.crtc);
> > - u8 buf;
> > - int ret = 0;
> > - int count = 0;
> > - int attempts = 10;
> > + int count = 0, ret = 0, attempts;
> >
> > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0) {
> > - DRM_DEBUG_KMS("Sink CRC couldn't be stopped properly\n");
> > - ret = -EIO;
> > - goto out;
> > - }
> > + for (attempts = 0; attempts < 3 && count == 0; attempts++) {
> > + u8 buf;
> >
> > - if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK,
> > - buf & ~DP_TEST_SINK_START) < 0) {
> > - DRM_DEBUG_KMS("Sink CRC couldn't be stopped properly\n");
> > - ret = -EIO;
> > - goto out;
> > - }
> > -
> > - do {
> > - intel_wait_for_vblank(dev_priv, intel_crtc->pipe);
> > + /* Wait for approximately half a frame, we cannot wait for a
>
> that should be dependend on the mode timings right?!
> I mean, I'm not against some random value that matches most used cases,
> but I believe the statement should be different.
>
I'll modify the comment, thanks!
Is there an existing function that provides this number in
milliseconds?
> > + * vblank interrupt as it triggers PSR exit.
> > + */
> > + if (attempts)
> > + usleep_range(8000, 8500);
> >
> > if (drm_dp_dpcd_readb(&intel_dp->aux,
> > DP_TEST_SINK_MISC, &buf) < 0) {
> > @@ -3909,93 +3895,19 @@ static int intel_dp_sink_crc_stop(struct intel_dp *intel_dp,
> > goto out;
> > }
> > count = buf & DP_TEST_COUNT_MASK;
> > - } while (--attempts && count);
> > -
> > - if (attempts == 0) {
> > - DRM_DEBUG_KMS("TIMEOUT: Sink CRC counter is not zeroed after calculation is stopped\n");
> > - ret = -ETIMEDOUT;
> > }
> >
> > - out:
> > - if (disable_wa)
> > - hsw_enable_ips(crtc_state);
> > - return ret;
> > -}
> > -
> > -static int intel_dp_sink_crc_start(struct intel_dp *intel_dp,
> > - struct intel_crtc_state *crtc_state)
> > -{
> > - struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
> > - struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> > - struct intel_crtc *intel_crtc = to_intel_crtc(crtc_state->base.crtc);
> > - u8 buf;
> > - int ret;
> > -
> > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf) < 0)
> > - return -EIO;
> > -
> > - if (!(buf & DP_TEST_CRC_SUPPORTED))
> > - return -ENOTTY;
> > -
> > - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0)
> > - return -EIO;
> > -
> > - if (buf & DP_TEST_SINK_START) {
> > - ret = intel_dp_sink_crc_stop(intel_dp, crtc_state, false);
> > - if (ret)
> > - return ret;
> > - }
> > -
> > - hsw_disable_ips(crtc_state);
> > -
> > - if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK,
> > - buf | DP_TEST_SINK_START) < 0) {
> > - hsw_enable_ips(crtc_state);
> > - return -EIO;
> > - }
> > -
> > - intel_wait_for_vblank(dev_priv, intel_crtc->pipe);
> > - return 0;
> > -}
> > -
> > -int intel_dp_sink_crc(struct intel_dp *intel_dp, struct intel_crtc_state *crtc_state, u8 *crc)
> > -{
> > - struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
> > - struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> > - struct intel_crtc *intel_crtc = to_intel_crtc(crtc_state->base.crtc);
> > - u8 buf;
> > - int count, ret;
> > - int attempts = 6;
> > -
> > - ret = intel_dp_sink_crc_start(intel_dp, crtc_state);
> > - if (ret)
> > - return ret;
> > -
> > - do {
> > - intel_wait_for_vblank(dev_priv, intel_crtc->pipe);
> > -
> > - if (drm_dp_dpcd_readb(&intel_dp->aux,
> > - DP_TEST_SINK_MISC, &buf) < 0) {
> > - ret = -EIO;
> > - goto stop;
> > - }
> > - count = buf & DP_TEST_COUNT_MASK;
> > -
> > - } while (--attempts && count == 0);
> > -
> > - if (attempts == 0) {
> > - DRM_ERROR("Panel is unable to calculate any CRC after 6 vblanks\n");
> > + if (attempts == 3) {
> > ret = -ETIMEDOUT;
> > - goto stop;
> > + goto out;
> > }
> >
> > if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) != 6) {
> > ret = -EIO;
> > - goto stop;
> > + goto out;
> > }
> >
> > -stop:
> > - intel_dp_sink_crc_stop(intel_dp, crtc_state, true);
> > +out:
> > return ret;
> > }
> >
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 44ed248f1fe9..cacee94749e2 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1644,8 +1644,7 @@ void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode);
> > void intel_dp_encoder_reset(struct drm_encoder *encoder);
> > void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
> > void intel_dp_encoder_destroy(struct drm_encoder *encoder);
> > -int intel_dp_sink_crc(struct intel_dp *intel_dp,
> > - struct intel_crtc_state *crtc_state, u8 *crc);
> > +int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc);
> > bool intel_dp_compute_config(struct intel_encoder *encoder,
> > struct intel_crtc_state *pipe_config,
> > struct drm_connector_state *conn_state);
> > --
> > 2.14.1
> >
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