Re: [Intel-gfx] [PATCH] drm/i915/hdcp: Avoid duplicate HDCP enables
On Thu, May 21, 2020 at 5:36 AM Anshuman Gupta wrote:
>
> On 2020-05-21 at 10:27:21 +0530, Ramalingam C wrote:
> > On 2020-05-20 at 15:47:44 -0400, Sean Paul wrote:
> > > From: Sean Paul
> > >
> > > If userspace sets the CP property to DESIRED while it's already ENABLED,
> > > the driver will try to re-enable HDCP. On some displays, this will
> > > result in R0' mismatches. I'm guessing this is because the display is
> > > still sending back Ri instead of re-authenticating.
> > >
> > > At any rate, we can fix this inefficiency easily enough by just nooping
> > > the DESIRED property set if HDCP is already ENABLED.
> AFAIU may below patch also solves above issue implicitly.
> https://patchwork.freedesktop.org/patch/365758/?series=72251=4
> Besides that +1 for below Ram comment, it would be better if such type of
> duplicate
> enable request should filter by drm_atomic_connector_set_property().
Thanks Anshuman, I didn't see that patch. Indeed that seems like it
accomplishes the same thing.
Let's drop this.
Sean
> Thanks,
> Anshuman Gupta.
>
> > Sean,
> >
> > This will skip the hdcp enable.
> >
> > But at present too we will be getting below WARN_ON from intel_hdcp_enable,
> > to indicate userspace is going wrong with request.
> > drm_WARN_ON(_priv->drm,
> > hdcp->value == DRM_MODE_CONTENT_PROTECTION_ENABLED);
> >
> > And if we need to filter this out, could we validate the incoming hdcp
> > request at
> > drm_atomic_connector_set_property() itself? No point in going into the
> > atomic commit without a valid request. something like
> >
> > diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
> > b/drivers/gpu/drm/drm_atomic_uapi.c
> > index a1e5e262bae2..d98b2eeae78d 100644
> > --- a/drivers/gpu/drm/drm_atomic_uapi.c
> > +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> > @@ -746,6 +746,12 @@ static int drm_atomic_connector_set_property(struct
> > drm_connector *connector,
> > DRM_DEBUG_KMS("only drivers can set CP Enabled\n");
> > return -EINVAL;
> > }
> > + if (config->content_protection_property ==
> > + DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> > + val == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
> > + DRM_DEBUG_KMS("Redundant req for content
> > protection\n");
> > + return -EINVAL;
> > + }
> > state->content_protection = val;
> > } else if (property == config->hdcp_content_type_property) {
> > state->hdcp_content_type = val;
> >
> > -Ram
> >
> > >
> > > Signed-off-by: Sean Paul
> > > ---
> > >
> > > I suspect this is the actual root cause I was chasing with
> > > "drm/i915/hdcp: Add additional R0' wait". I was able to reproduce the
> > > R0` messages by marking HDCP desired while it was already enabled. This
> > > _should_ work, but it seems like some displays handle it more graciously
> > > than others.
> > >
> > >
> > > drivers/gpu/drm/i915/display/intel_hdcp.c | 10 +++---
> > > 1 file changed, 7 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > index 2cbc4619b4ce..f770fe0c5595 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > @@ -2156,12 +2156,16 @@ void intel_hdcp_atomic_check(struct drm_connector
> > > *connector,
> > > }
> > >
> > > /*
> > > -* Nothing to do if the state didn't change, or HDCP was activated
> > > since
> > > -* the last commit. And also no change in hdcp content type.
> > > +* Nothing to do if content type is unchanged and one of:
> > > +* - state didn't change
> > > +* - HDCP was activated since the last commit
> > > +* - attempting to set to desired while already enabled
> > > */
> > > if (old_cp == new_cp ||
> > > (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
> > > -new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)) {
> > > +new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED) ||
> > > + (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> > > +new_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED)) {
> > > if (old_state->hdcp_content_type ==
> > > new_state->hdcp_content_type)
> > > return;
> > > --
> > > Sean Paul, Software Engineer, Google / Chromium OS
> > >
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Re: [Intel-gfx] [PATCH] drm/i915/hdcp: Avoid duplicate HDCP enables
On 2020-05-21 at 10:27:21 +0530, Ramalingam C wrote:
> On 2020-05-20 at 15:47:44 -0400, Sean Paul wrote:
> > From: Sean Paul
> >
> > If userspace sets the CP property to DESIRED while it's already ENABLED,
> > the driver will try to re-enable HDCP. On some displays, this will
> > result in R0' mismatches. I'm guessing this is because the display is
> > still sending back Ri instead of re-authenticating.
> >
> > At any rate, we can fix this inefficiency easily enough by just nooping
> > the DESIRED property set if HDCP is already ENABLED.
AFAIU may below patch also solves above issue implicitly.
https://patchwork.freedesktop.org/patch/365758/?series=72251=4
Besides that +1 for below Ram comment, it would be better if such type of
duplicate
enable request should filter by drm_atomic_connector_set_property().
Thanks,
Anshuman Gupta.
> Sean,
>
> This will skip the hdcp enable.
>
> But at present too we will be getting below WARN_ON from intel_hdcp_enable,
> to indicate userspace is going wrong with request.
> drm_WARN_ON(_priv->drm,
> hdcp->value == DRM_MODE_CONTENT_PROTECTION_ENABLED);
>
> And if we need to filter this out, could we validate the incoming hdcp
> request at
> drm_atomic_connector_set_property() itself? No point in going into the
> atomic commit without a valid request. something like
>
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
> b/drivers/gpu/drm/drm_atomic_uapi.c
> index a1e5e262bae2..d98b2eeae78d 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -746,6 +746,12 @@ static int drm_atomic_connector_set_property(struct
> drm_connector *connector,
> DRM_DEBUG_KMS("only drivers can set CP Enabled\n");
> return -EINVAL;
> }
> + if (config->content_protection_property ==
> + DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> + val == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
> + DRM_DEBUG_KMS("Redundant req for content
> protection\n");
> + return -EINVAL;
> + }
> state->content_protection = val;
> } else if (property == config->hdcp_content_type_property) {
> state->hdcp_content_type = val;
>
> -Ram
>
> >
> > Signed-off-by: Sean Paul
> > ---
> >
> > I suspect this is the actual root cause I was chasing with
> > "drm/i915/hdcp: Add additional R0' wait". I was able to reproduce the
> > R0` messages by marking HDCP desired while it was already enabled. This
> > _should_ work, but it seems like some displays handle it more graciously
> > than others.
> >
> >
> > drivers/gpu/drm/i915/display/intel_hdcp.c | 10 +++---
> > 1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > index 2cbc4619b4ce..f770fe0c5595 100644
> > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > @@ -2156,12 +2156,16 @@ void intel_hdcp_atomic_check(struct drm_connector
> > *connector,
> > }
> >
> > /*
> > -* Nothing to do if the state didn't change, or HDCP was activated since
> > -* the last commit. And also no change in hdcp content type.
> > +* Nothing to do if content type is unchanged and one of:
> > +* - state didn't change
> > +* - HDCP was activated since the last commit
> > +* - attempting to set to desired while already enabled
> > */
> > if (old_cp == new_cp ||
> > (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
> > -new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)) {
> > +new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED) ||
> > + (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> > +new_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED)) {
> > if (old_state->hdcp_content_type ==
> > new_state->hdcp_content_type)
> > return;
> > --
> > Sean Paul, Software Engineer, Google / Chromium OS
> >
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Re: [Intel-gfx] [PATCH] drm/i915/hdcp: Avoid duplicate HDCP enables
On 2020-05-20 at 15:47:44 -0400, Sean Paul wrote:
> From: Sean Paul
>
> If userspace sets the CP property to DESIRED while it's already ENABLED,
> the driver will try to re-enable HDCP. On some displays, this will
> result in R0' mismatches. I'm guessing this is because the display is
> still sending back Ri instead of re-authenticating.
>
> At any rate, we can fix this inefficiency easily enough by just nooping
> the DESIRED property set if HDCP is already ENABLED.
Sean,
This will skip the hdcp enable.
But at present too we will be getting below WARN_ON from intel_hdcp_enable,
to indicate userspace is going wrong with request.
drm_WARN_ON(_priv->drm,
hdcp->value == DRM_MODE_CONTENT_PROTECTION_ENABLED);
And if we need to filter this out, could we validate the incoming hdcp request
at
drm_atomic_connector_set_property() itself? No point in going into the
atomic commit without a valid request. something like
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
b/drivers/gpu/drm/drm_atomic_uapi.c
index a1e5e262bae2..d98b2eeae78d 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -746,6 +746,12 @@ static int drm_atomic_connector_set_property(struct
drm_connector *connector,
DRM_DEBUG_KMS("only drivers can set CP Enabled\n");
return -EINVAL;
}
+ if (config->content_protection_property ==
+ DRM_MODE_CONTENT_PROTECTION_ENABLED &&
+ val == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
+ DRM_DEBUG_KMS("Redundant req for content protection\n");
+ return -EINVAL;
+ }
state->content_protection = val;
} else if (property == config->hdcp_content_type_property) {
state->hdcp_content_type = val;
-Ram
>
> Signed-off-by: Sean Paul
> ---
>
> I suspect this is the actual root cause I was chasing with
> "drm/i915/hdcp: Add additional R0' wait". I was able to reproduce the
> R0` messages by marking HDCP desired while it was already enabled. This
> _should_ work, but it seems like some displays handle it more graciously
> than others.
>
>
> drivers/gpu/drm/i915/display/intel_hdcp.c | 10 +++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 2cbc4619b4ce..f770fe0c5595 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -2156,12 +2156,16 @@ void intel_hdcp_atomic_check(struct drm_connector
> *connector,
> }
>
> /*
> - * Nothing to do if the state didn't change, or HDCP was activated since
> - * the last commit. And also no change in hdcp content type.
> + * Nothing to do if content type is unchanged and one of:
> + * - state didn't change
> + * - HDCP was activated since the last commit
> + * - attempting to set to desired while already enabled
>*/
> if (old_cp == new_cp ||
> (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
> - new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)) {
> + new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED) ||
> + (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> + new_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED)) {
> if (old_state->hdcp_content_type ==
> new_state->hdcp_content_type)
> return;
> --
> Sean Paul, Software Engineer, Google / Chromium OS
>
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