[PATCH 1/2] drm/i915: Call intel_dp_mst_resume() before resuming displays

[PATCH 1/2] drm/i915: Call intel_dp_mst_resume() before resuming displays

[Lyude]

Since we need MST devices ready before we try to resume displays,
calling this after intel_display_resume() can result in some issues with
various laptop docks where the monitor won't turn back on after
suspending the system.

This order was originally changed in

	commit e7d6f7d70829 ("drm/i915: resume MST after reading back hw state")

In order to fix some unclaimed register errors, however the actual cause
of those has since been fixed.

CC: stable@vger.kernel.org
Signed-off-by: Lyude <cpaul@redhat.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f357058..08854ae 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -761,12 +761,12 @@ static int i915_drm_resume(struct drm_device *dev)
 		dev_priv->display.hpd_irq_setup(dev);
 	spin_unlock_irq(&dev_priv->irq_lock);
 
+	intel_dp_mst_resume(dev);
+
 	drm_modeset_lock_all(dev);
 	intel_display_resume(dev);
 	drm_modeset_unlock_all(dev);
 
-	intel_dp_mst_resume(dev);
-
 	/*
 	 * ... but also need to make sure that hotplug processing
 	 * doesn't cause havoc. Like in the driver load code we don't
-- 
2.5.0

[PATCH 2/2] drm/i915: Retry after 30ms if we fail to resume DP MST

[Lyude]

For whatever reason, I've found that some laptops aren't immediately
capable of doing aux transactions with their docks when they come out of
standby. While I'm still not entirely sure what the cause of this is,
sleeping for 30ms and then retrying drm_dp_mst_topology_mgr_resume()
should be a sufficient enough workaround until we find a real fix.

CC: stable@vger.kernel.org
Signed-off-by: Lyude <cpaul@redhat.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1d8de43..8cc5f6f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -6114,6 +6114,19 @@ void intel_dp_mst_resume(struct drm_device *dev)
 
 			ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr);
 			if (ret != 0) {
+				/*
+				 * For some reason, some laptops can't bring
+				 * their MST docks back up immediately after
+				 * resume and need to wait a short period of
+				 * time before aux transactions with the dock
+				 * become functional again. Until we find a
+				 * proper fix for this, this workaround should
+				 * suffice
+				 */
+				msleep(30);
+				ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr);
+			}
+			if (ret != 0) {
 				intel_dp_check_mst_status(&intel_dig_port->dp);
 			}
 		}
-- 
2.5.0

Re: [PATCH 2/2] drm/i915: Retry after 30ms if we fail to resume DP MST

[Daniel Vetter]

On Fri, Mar 11, 2016 at 10:57:02AM -0500, Lyude wrote:
> For whatever reason, I've found that some laptops aren't immediately
> capable of doing aux transactions with their docks when they come out of
> standby. While I'm still not entirely sure what the cause of this is,
> sleeping for 30ms and then retrying drm_dp_mst_topology_mgr_resume()
> should be a sufficient enough workaround until we find a real fix.
> 
> CC: stable@vger.kernel.org
> Signed-off-by: Lyude <cpaul@redhat.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 1d8de43..8cc5f6f 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -6114,6 +6114,19 @@ void intel_dp_mst_resume(struct drm_device *dev)
>  
>  			ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr);
>  			if (ret != 0) {
> +				/*
> +				 * For some reason, some laptops can't bring
> +				 * their MST docks back up immediately after
> +				 * resume and need to wait a short period of
> +				 * time before aux transactions with the dock
> +				 * become functional again. Until we find a
> +				 * proper fix for this, this workaround should
> +				 * suffice
> +				 */
> +				msleep(30);
> +				ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr);
> +			}

Hm, since it's the dp aux that fails (and not something higher up
apparently) shouldnt' we have this massive retry somewhere in the dp aux
helpers maybe? DP resume in general is a bit fragile, maybe we're just
missing a lot of retries in general?

Either way this needs a lot more details. Comment definitely should start
out with FIXME, and the commit message should have a protocol of all the
experiments you've done thus far. Yes this means a ridiculously long
commit message, but in roughly 2 weeks someone else will go wtf on this,
and then they must be able to read up the full story. And we need links to
bugzillas and mail threads, too.

And please Cc: Art with this one too.

Thanks, Daniel

> +			if (ret != 0) {
>  				intel_dp_check_mst_status(&intel_dig_port->dp);
>  			}
>  		}
> -- 
> 2.5.0
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 1/2] drm/i915: Call intel_dp_mst_resume() before resuming displays

[Daniel Vetter]

On Fri, Mar 11, 2016 at 10:57:01AM -0500, Lyude wrote:
> Since we need MST devices ready before we try to resume displays,
> calling this after intel_display_resume() can result in some issues with
> various laptop docks where the monitor won't turn back on after
> suspending the system.
> 
> This order was originally changed in
> 
> 	commit e7d6f7d70829 ("drm/i915: resume MST after reading back hw state")
> 
> In order to fix some unclaimed register errors, however the actual cause
> of those has since been fixed.
> 
> CC: stable@vger.kernel.org
> Signed-off-by: Lyude <cpaul@redhat.com>

Don't we need to first apply patch 2/2 to avoid breaking systems
in-between?
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index f357058..08854ae 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -761,12 +761,12 @@ static int i915_drm_resume(struct drm_device *dev)
>  		dev_priv->display.hpd_irq_setup(dev);
>  	spin_unlock_irq(&dev_priv->irq_lock);
>  
> +	intel_dp_mst_resume(dev);
> +
>  	drm_modeset_lock_all(dev);
>  	intel_display_resume(dev);
>  	drm_modeset_unlock_all(dev);
>  
> -	intel_dp_mst_resume(dev);
> -
>  	/*
>  	 * ... but also need to make sure that hotplug processing
>  	 * doesn't cause havoc. Like in the driver load code we don't
> -- 
> 2.5.0
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [Intel-gfx] [PATCH 1/2] drm/i915: Call intel_dp_mst_resume() before resuming displays

[Lyude Paul]

On Sun, 2016-03-13 at 19:45 +0100, Daniel Vetter wrote:
> On Fri, Mar 11, 2016 at 10:57:01AM -0500, Lyude wrote:
> > 
> > Since we need MST devices ready before we try to resume displays,
> > calling this after intel_display_resume() can result in some issues with
> > various laptop docks where the monitor won't turn back on after
> > suspending the system.
> > 
> > This order was originally changed in
> > 
> > 	commit e7d6f7d70829 ("drm/i915: resume MST after reading back hw state")
> > 
> > In order to fix some unclaimed register errors, however the actual cause
> > of those has since been fixed.
> > 
> > CC: stable@vger.kernel.org
> > Signed-off-by: Lyude <cpaul@redhat.com>
> Don't we need to first apply patch 2/2 to avoid breaking systems
> in-between?
> -Daniel
AFAICT the warns don't appear even with this patch, so no.
> 
> > 
> > ---
> >  drivers/gpu/drm/i915/i915_drv.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c
> > b/drivers/gpu/drm/i915/i915_drv.c
> > index f357058..08854ae 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -761,12 +761,12 @@ static int i915_drm_resume(struct drm_device *dev)
> >  		dev_priv->display.hpd_irq_setup(dev);
> >  	spin_unlock_irq(&dev_priv->irq_lock);
> >  
> > +	intel_dp_mst_resume(dev);
> > +
> >  	drm_modeset_lock_all(dev);
> >  	intel_display_resume(dev);
> >  	drm_modeset_unlock_all(dev);
> >  
> > -	intel_dp_mst_resume(dev);
> > -
> >  	/*
> >  	 * ... but also need to make sure that hotplug processing
> >  	 * doesn't cause havoc. Like in the driver load code we don't
> > -- 
> > 2.5.0
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [Intel-gfx] [PATCH 1/2] drm/i915: Call intel_dp_mst_resume() before resuming displays

[Lyude Paul]

bump

Could we get a reviewed-by for this patch? It's needed in addition to the patch
series I sent for removing intel_dp_dpcd_read_wake() for the T560 to have it's
monitors work properly on resume.

On Wed, 2016-03-16 at 17:49 -0400, Lyude Paul wrote:
> On Sun, 2016-03-13 at 19:45 +0100, Daniel Vetter wrote:
> > 
> > On Fri, Mar 11, 2016 at 10:57:01AM -0500, Lyude wrote:
> > > 
> > > 
> > > Since we need MST devices ready before we try to resume displays,
> > > calling this after intel_display_resume() can result in some issues with
> > > various laptop docks where the monitor won't turn back on after
> > > suspending the system.
> > > 
> > > This order was originally changed in
> > > 
> > > 	commit e7d6f7d70829 ("drm/i915: resume MST after reading back hw state")
> > > 
> > > In order to fix some unclaimed register errors, however the actual cause
> > > of those has since been fixed.
> > > 
> > > CC: stable@vger.kernel.org
> > > Signed-off-by: Lyude <cpaul@redhat.com>
> > Don't we need to first apply patch 2/2 to avoid breaking systems
> > in-between?
> > -Daniel
> AFAICT the warns don't appear even with this patch, so no.
> > 
> > 
> > > 
> > > 
> > > ---
> > >  drivers/gpu/drm/i915/i915_drv.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.c
> > > b/drivers/gpu/drm/i915/i915_drv.c
> > > index f357058..08854ae 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.c
> > > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > > @@ -761,12 +761,12 @@ static int i915_drm_resume(struct drm_device *dev)
> > >  		dev_priv->display.hpd_irq_setup(dev);
> > >  	spin_unlock_irq(&dev_priv->irq_lock);
> > >  
> > > +	intel_dp_mst_resume(dev);
> > > +
> > >  	drm_modeset_lock_all(dev);
> > >  	intel_display_resume(dev);
> > >  	drm_modeset_unlock_all(dev);
> > >  
> > > -	intel_dp_mst_resume(dev);
> > > -
> > >  	/*
> > >  	 * ... but also need to make sure that hotplug processing
> > >  	 * doesn't cause havoc. Like in the driver load code we don't
> > > -- 
> > > 2.5.0
> > > 
> > > _______________________________________________
> > > Intel-gfx mailing list
> > > Intel-gfx@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
-- 
Cheers,
	Lyude

Re: [Intel-gfx] [PATCH 1/2] drm/i915: Call intel_dp_mst_resume() before resuming displays

[Daniel Vetter]

On Tue, Mar 29, 2016 at 10:11:54AM -0400, Lyude Paul wrote:
> bump
> 
> Could we get a reviewed-by for this patch? It's needed in addition to the patch
> series I sent for removing intel_dp_dpcd_read_wake() for the T560 to have it's
> monitors work properly on resume.

Applied, thanks.
-Daniel

> 
> On Wed, 2016-03-16 at 17:49 -0400, Lyude Paul wrote:
> > On Sun, 2016-03-13 at 19:45 +0100, Daniel Vetter wrote:
> > > 
> > > On Fri, Mar 11, 2016 at 10:57:01AM -0500, Lyude wrote:
> > > > 
> > > > 
> > > > Since we need MST devices ready before we try to resume displays,
> > > > calling this after intel_display_resume() can result in some issues with
> > > > various laptop docks where the monitor won't turn back on after
> > > > suspending the system.
> > > > 
> > > > This order was originally changed in
> > > > 
> > > > 	commit e7d6f7d70829 ("drm/i915: resume MST after reading back hw state")
> > > > 
> > > > In order to fix some unclaimed register errors, however the actual cause
> > > > of those has since been fixed.
> > > > 
> > > > CC: stable@vger.kernel.org
> > > > Signed-off-by: Lyude <cpaul@redhat.com>
> > > Don't we need to first apply patch 2/2 to avoid breaking systems
> > > in-between?
> > > -Daniel
> > AFAICT the warns don't appear even with this patch, so no.
> > > 
> > > 
> > > > 
> > > > 
> > > > ---
> > > > �drivers/gpu/drm/i915/i915_drv.c | 4 ++--
> > > > �1 file changed, 2 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c
> > > > b/drivers/gpu/drm/i915/i915_drv.c
> > > > index f357058..08854ae 100644
> > > > --- a/drivers/gpu/drm/i915/i915_drv.c
> > > > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > > > @@ -761,12 +761,12 @@ static int i915_drm_resume(struct drm_device *dev)
> > > > �		dev_priv->display.hpd_irq_setup(dev);
> > > > �	spin_unlock_irq(&dev_priv->irq_lock);
> > > > �
> > > > +	intel_dp_mst_resume(dev);
> > > > +
> > > > �	drm_modeset_lock_all(dev);
> > > > �	intel_display_resume(dev);
> > > > �	drm_modeset_unlock_all(dev);
> > > > �
> > > > -	intel_dp_mst_resume(dev);
> > > > -
> > > > �	/*
> > > > �	�* ... but also need to make sure that hotplug processing
> > > > �	�* doesn't cause havoc. Like in the driver load code we don't
> > > > --�
> > > > 2.5.0
> > > > 
> > > > _______________________________________________
> > > > Intel-gfx mailing list
> > > > Intel-gfx@lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> -- 
> Cheers,
> 	Lyude
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch