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Message-ID: <20221227204003.6b0abe65@alexey-Swift-SF314-42>
Date: Tue, 27 Dec 2022 20:40:03 +0300
From: Alexey Lukyachuk <skif@...f-web.ru>
To: Rodrigo Vivi <rodrigo.vivi@...el.com>
Cc: <tvrtko.ursulin@...ux.intel.com>,
<dri-devel@...ts.freedesktop.org>,
"Greg Kroah-Hartman" <gregkh@...uxfoundation.org>,
<intel-gfx@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>,
<stable@...r.kernel.org>, Daniel Vetter <daniel@...ll.ch>,
David Airlie <airlied@...il.com>
Subject: Re: [Intel-gfx] [PATCH v2] drm/i915: dell wyse 3040 shutdown fix
On Tue, 27 Dec 2022 11:39:25 -0500
Rodrigo Vivi <rodrigo.vivi@...el.com> wrote:
> On Sun, Dec 25, 2022 at 09:55:08PM +0300, Alexey Lukyanchuk wrote:
> > dell wyse 3040 doesn't peform poweroff properly, but instead remains in
> > turned power on state.
>
> okay, the motivation is explained in the commit msg..
>
> > Additional mutex_lock and
> > intel_crtc_wait_for_next_vblank
> > feature 6.2 kernel resolve this trouble.
>
> but this why is not very clear... seems that by magic it was found,
> without explaining what race we are really protecting here.
>
> but even worse is:
> what about those many random vblank waits in the code? what's the
> reasoning?
>
> >
> > cc: stable@...r.kernel.org
> > original commit Link: https://patchwork.freedesktop.org/patch/508926/
> > fixes: fe0f1e3bfdfeb53e18f1206aea4f40b9bd1f291c
> > Signed-off-by: Alexey Lukyanchuk <skif@...f-web.ru>
> > ---
> > I got some troubles with this device (dell wyse 3040) since kernel 5.11
> > started to use i915_driver_shutdown function. I found solution here:
> >
> > https://lore.kernel.org/dri-devel/Y1wd6ZJ8LdJpCfZL@intel.com/#r
> >
> > ---
> > drivers/gpu/drm/i915/display/intel_audio.c | 37 +++++++++++++++-------
> > 1 file changed, 25 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
> > index aacbc6da8..44344ecdf 100644
> > --- a/drivers/gpu/drm/i915/display/intel_audio.c
> > +++ b/drivers/gpu/drm/i915/display/intel_audio.c
> > @@ -336,6 +336,7 @@ static void g4x_audio_codec_disable(struct intel_encoder *encoder,
> > const struct drm_connector_state *old_conn_state)
> > {
> > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > + struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
> > u32 eldv, tmp;
> >
> > tmp = intel_de_read(dev_priv, G4X_AUD_VID_DID);
> > @@ -348,6 +349,9 @@ static void g4x_audio_codec_disable(struct intel_encoder *encoder,
> > tmp = intel_de_read(dev_priv, G4X_AUD_CNTL_ST);
> > tmp &= ~eldv;
> > intel_de_write(dev_priv, G4X_AUD_CNTL_ST, tmp);
> > +
> > + intel_crtc_wait_for_next_vblank(crtc);
> > + intel_crtc_wait_for_next_vblank(crtc);
> > }
> >
> > static void g4x_audio_codec_enable(struct intel_encoder *encoder,
> > @@ -355,12 +359,15 @@ static void g4x_audio_codec_enable(struct intel_encoder *encoder,
> > const struct drm_connector_state *conn_state)
> > {
> > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > struct drm_connector *connector = conn_state->connector;
> > const u8 *eld = connector->eld;
> > u32 eldv;
> > u32 tmp;
> > int len, i;
> >
> > + intel_crtc_wait_for_next_vblank(crtc);
> > +
> > tmp = intel_de_read(dev_priv, G4X_AUD_VID_DID);
> > if (tmp == INTEL_AUDIO_DEVBLC || tmp == INTEL_AUDIO_DEVCL)
> > eldv = G4X_ELDV_DEVCL_DEVBLC;
> > @@ -493,6 +500,7 @@ static void hsw_audio_codec_disable(struct intel_encoder *encoder,
> > const struct drm_connector_state *old_conn_state)
> > {
> > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > + struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
> > enum transcoder cpu_transcoder = old_crtc_state->cpu_transcoder;
> > u32 tmp;
> >
> > @@ -508,6 +516,10 @@ static void hsw_audio_codec_disable(struct intel_encoder *encoder,
> > tmp |= AUD_CONFIG_N_VALUE_INDEX;
> > intel_de_write(dev_priv, HSW_AUD_CFG(cpu_transcoder), tmp);
> >
> > +
> > + intel_crtc_wait_for_next_vblank(crtc);
> > + intel_crtc_wait_for_next_vblank(crtc);
> > +
> > /* Invalidate ELD */
> > tmp = intel_de_read(dev_priv, HSW_AUD_PIN_ELD_CP_VLD);
> > tmp &= ~AUDIO_ELD_VALID(cpu_transcoder);
> > @@ -633,6 +645,7 @@ static void hsw_audio_codec_enable(struct intel_encoder *encoder,
> > const struct drm_connector_state *conn_state)
> > {
> > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > struct drm_connector *connector = conn_state->connector;
> > enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> > const u8 *eld = connector->eld;
> > @@ -651,12 +664,7 @@ static void hsw_audio_codec_enable(struct intel_encoder *encoder,
> > tmp &= ~AUDIO_ELD_VALID(cpu_transcoder);
> > intel_de_write(dev_priv, HSW_AUD_PIN_ELD_CP_VLD, tmp);
> >
> > - /*
> > - * FIXME: We're supposed to wait for vblank here, but we have vblanks
> > - * disabled during the mode set. The proper fix would be to push the
> > - * rest of the setup into a vblank work item, queued here, but the
> > - * infrastructure is not there yet.
> > - */
> > + intel_crtc_wait_for_next_vblank(crtc);
> >
> > /* Reset ELD write address */
> > tmp = intel_de_read(dev_priv, HSW_AUD_DIP_ELD_CTRL(cpu_transcoder));
> > @@ -705,6 +713,8 @@ static void ilk_audio_codec_disable(struct intel_encoder *encoder,
> > aud_cntrl_st2 = CPT_AUD_CNTRL_ST2;
> > }
> >
> > + mutex_lock(&dev_priv->display.audio.mutex);
> > +
> > /* Disable timestamps */
> > tmp = intel_de_read(dev_priv, aud_config);
> > tmp &= ~AUD_CONFIG_N_VALUE_INDEX;
> > @@ -721,6 +731,10 @@ static void ilk_audio_codec_disable(struct intel_encoder *encoder,
> > tmp = intel_de_read(dev_priv, aud_cntrl_st2);
> > tmp &= ~eldv;
> > intel_de_write(dev_priv, aud_cntrl_st2, tmp);
> > + mutex_unlock(&dev_priv->display.audio.mutex);
> > +
> > + intel_crtc_wait_for_next_vblank(crtc);
> > + intel_crtc_wait_for_next_vblank(crtc);
> > }
> >
> > static void ilk_audio_codec_enable(struct intel_encoder *encoder,
> > @@ -740,12 +754,7 @@ static void ilk_audio_codec_enable(struct intel_encoder *encoder,
> > if (drm_WARN_ON(&dev_priv->drm, port == PORT_A))
> > return;
> >
> > - /*
> > - * FIXME: We're supposed to wait for vblank here, but we have vblanks
> > - * disabled during the mode set. The proper fix would be to push the
> > - * rest of the setup into a vblank work item, queued here, but the
> > - * infrastructure is not there yet.
> > - */
> > + intel_crtc_wait_for_next_vblank(crtc);
> >
> > if (HAS_PCH_IBX(dev_priv)) {
> > hdmiw_hdmiedid = IBX_HDMIW_HDMIEDID(pipe);
> > @@ -767,6 +776,8 @@ static void ilk_audio_codec_enable(struct intel_encoder *encoder,
> >
> > eldv = IBX_ELD_VALID(port);
> >
> > + mutex_lock(&dev_priv->display.audio.mutex);
> > +
> > /* Invalidate ELD */
> > tmp = intel_de_read(dev_priv, aud_cntrl_st2);
> > tmp &= ~eldv;
> > @@ -798,6 +809,8 @@ static void ilk_audio_codec_enable(struct intel_encoder *encoder,
> > else
> > tmp |= audio_config_hdmi_pixel_clock(crtc_state);
> > intel_de_write(dev_priv, aud_config, tmp);
> > +
> > + mutex_unlock(&dev_priv->display.audio.mutex);
> > }
> >
> > /**
> > --
> > 2.25.1
> >
I would like to say, that this solution was found in drm-tip repository:
link: git://anongit.freedesktop.org/drm-tip
I will quotate original commit message from Ville Syrjälä
<ville.syrjala@...ux.intel.com>: "The spec tells us to do a bunch of
vblank waits in the audio enable/disable sequences. Make it so."
So it's just a backport of accepted patch.
Which i wanna to propagate to stable versions
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