Re: [Nouveau] [RFC 19/20] drm/i915/dp: Extract drm_dp_read_dpcd_caps()
On Wed, 2020-08-19 at 11:29 -0400, Sean Paul wrote:
> On Tue, Aug 11, 2020 at 04:04:56PM -0400, Lyude Paul wrote:
> > Since DP 1.3, it's been possible for DP receivers to specify an
> > additional set of DPCD capabilities, which can take precedence over the
> > capabilities reported at DP_DPCD_REV.
> >
> > Basically any device supporting DP is going to need to read these in an
> > identical manner, in particular nouveau, so let's go ahead and just move
> > this code out of i915 into a shared DRM DP helper that we can use in
> > other drivers.
> >
> > Signed-off-by: Lyude Paul
> > ---
> > drivers/gpu/drm/drm_dp_helper.c | 76 +
> > drivers/gpu/drm/i915/display/intel_dp.c | 60 +---
> > drivers/gpu/drm/i915/display/intel_dp.h | 1 -
> > drivers/gpu/drm/i915/display/intel_lspcon.c | 2 +-
> > include/drm/drm_dp_helper.h | 3 +
> > 5 files changed, 82 insertions(+), 60 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c
> > b/drivers/gpu/drm/drm_dp_helper.c
> > index 0ff2959c8f8e8..f9445915c6c26 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -423,6 +423,82 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux
> > *aux,
> > }
> > EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
> >
> > +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
> > + u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > + u8 dpcd_ext[6];
> > + int ret;
> > +
> > + /*
> > +* Prior to DP1.3 the bit represented by
> > +* DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
> > +* If it is set DP_DPCD_REV at h could be at a value less than
> > +* the true capability of the panel. The only way to check is to
> > +* then compare h and 2200h.
> > +*/
> > + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
> > + return 0;
> > +
> > + ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, _ext,
> > + sizeof(dpcd_ext));
> > + if (ret != sizeof(dpcd_ext))
> > + return -EIO;
> > +
> > + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
> > + DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d
> > > %d)\n",
> > + aux->name, dpcd[DP_DPCD_REV],
> > + dpcd_ext[DP_DPCD_REV]);
>
> Might be a good opportunity to convert all of these to drm_dbg_dp()?
Oh also - thought about this as well, but this would be easier as a follow-up
patch since we'd want to add a backpointer to the original DRM device (not 100%
sure we can just determine the drm device parent from the aux device's parent)
>
> > + return 0;
> > + }
> > +
> > + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
> > + return 0;
> > +
> > + DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
> > + aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
> > +
> > + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
> > + * available
> > + * @aux: DisplayPort AUX channel
> > + * @dpcd: Buffer to store the resulting DPCD in
> > + *
> > + * Attempts to read the base DPCD caps for @aux. Additionally, this
> > function
> > + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
> > + * present.
> > + *
> > + * Returns: %0 if the DPCD was read successfully, negative error code
> > + * otherwise.
> > + */
> > +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
> > + u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > + int ret;
> > +
> > + ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
> > + if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
> > + return -EIO;
> > +
> > + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
> > + if (ret < 0)
> > + return ret;
>
> I wonder if we should just go with the "regular" dpcd caps we just read in
> this
> case?
>
> Regardless of my nits,
>
> Reviewed-by: Sean Paul
>
> > +
> > + DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
> > + aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
> > +
> > + if (dpcd[DP_DPCD_REV] == 0)
> > + ret = -EIO;
> > +
> > + return ret;
> > +}
> > +EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
> > +
> > /**
> > * drm_dp_downstream_read_info() - read DPCD downstream port info if
> > available
> > * @aux: DisplayPort AUX channel
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index e343965a483df..230aa0360dc61 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4449,62 +4449,6 @@ intel_dp_link_down(struct intel_encoder *encoder,
> > }
> > }
> >
> > -static void
> > -intel_dp_extended_receiver_capabilities(struct intel_dp
Re: [Nouveau] [RFC 19/20] drm/i915/dp: Extract drm_dp_read_dpcd_caps()
On Wed, 2020-08-19 at 11:29 -0400, Sean Paul wrote:
> On Tue, Aug 11, 2020 at 04:04:56PM -0400, Lyude Paul wrote:
> > Since DP 1.3, it's been possible for DP receivers to specify an
> > additional set of DPCD capabilities, which can take precedence over the
> > capabilities reported at DP_DPCD_REV.
> >
> > Basically any device supporting DP is going to need to read these in an
> > identical manner, in particular nouveau, so let's go ahead and just move
> > this code out of i915 into a shared DRM DP helper that we can use in
> > other drivers.
> >
> > Signed-off-by: Lyude Paul
> > ---
> > drivers/gpu/drm/drm_dp_helper.c | 76 +
> > drivers/gpu/drm/i915/display/intel_dp.c | 60 +---
> > drivers/gpu/drm/i915/display/intel_dp.h | 1 -
> > drivers/gpu/drm/i915/display/intel_lspcon.c | 2 +-
> > include/drm/drm_dp_helper.h | 3 +
> > 5 files changed, 82 insertions(+), 60 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c
> > b/drivers/gpu/drm/drm_dp_helper.c
> > index 0ff2959c8f8e8..f9445915c6c26 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -423,6 +423,82 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux
> > *aux,
> > }
> > EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
> >
> > +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
> > + u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > + u8 dpcd_ext[6];
> > + int ret;
> > +
> > + /*
> > +* Prior to DP1.3 the bit represented by
> > +* DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
> > +* If it is set DP_DPCD_REV at h could be at a value less than
> > +* the true capability of the panel. The only way to check is to
> > +* then compare h and 2200h.
> > +*/
> > + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
> > + return 0;
> > +
> > + ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, _ext,
> > + sizeof(dpcd_ext));
> > + if (ret != sizeof(dpcd_ext))
> > + return -EIO;
> > +
> > + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
> > + DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d
> > > %d)\n",
> > + aux->name, dpcd[DP_DPCD_REV],
> > + dpcd_ext[DP_DPCD_REV]);
>
> Might be a good opportunity to convert all of these to drm_dbg_dp()?
>
> > + return 0;
> > + }
> > +
> > + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
> > + return 0;
> > +
> > + DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
> > + aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
> > +
> > + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
> > + * available
> > + * @aux: DisplayPort AUX channel
> > + * @dpcd: Buffer to store the resulting DPCD in
> > + *
> > + * Attempts to read the base DPCD caps for @aux. Additionally, this
> > function
> > + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
> > + * present.
> > + *
> > + * Returns: %0 if the DPCD was read successfully, negative error code
> > + * otherwise.
> > + */
> > +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
> > + u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > + int ret;
> > +
> > + ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
> > + if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
> > + return -EIO;
> > +
> > + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
> > + if (ret < 0)
> > + return ret;
>
> I wonder if we should just go with the "regular" dpcd caps we just read in
> this
> case?
FWIW - we generally want to just abort on failed DPCD reads since if a device
doesn't implement a feature like this, it'll usually read all zeroes. Failed
DPCD reads are almost always just the result of something suddenly being
disconnected (excluding some cases I've seen on MST, but I think those more have
to do with us sending incorrect dpcd read/write requests...)
>
> Regardless of my nits,
>
> Reviewed-by: Sean Paul
>
> > +
> > + DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
> > + aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
> > +
> > + if (dpcd[DP_DPCD_REV] == 0)
> > + ret = -EIO;
> > +
> > + return ret;
> > +}
> > +EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
> > +
> > /**
> > * drm_dp_downstream_read_info() - read DPCD downstream port info if
> > available
> > * @aux: DisplayPort AUX channel
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index e343965a483df..230aa0360dc61 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -4449,62 +4449,6 @@
Re: [Nouveau] [RFC 19/20] drm/i915/dp: Extract drm_dp_read_dpcd_caps()
On Tue, Aug 11, 2020 at 04:04:56PM -0400, Lyude Paul wrote:
> Since DP 1.3, it's been possible for DP receivers to specify an
> additional set of DPCD capabilities, which can take precedence over the
> capabilities reported at DP_DPCD_REV.
>
> Basically any device supporting DP is going to need to read these in an
> identical manner, in particular nouveau, so let's go ahead and just move
> this code out of i915 into a shared DRM DP helper that we can use in
> other drivers.
>
> Signed-off-by: Lyude Paul
> ---
> drivers/gpu/drm/drm_dp_helper.c | 76 +
> drivers/gpu/drm/i915/display/intel_dp.c | 60 +---
> drivers/gpu/drm/i915/display/intel_dp.h | 1 -
> drivers/gpu/drm/i915/display/intel_lspcon.c | 2 +-
> include/drm/drm_dp_helper.h | 3 +
> 5 files changed, 82 insertions(+), 60 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 0ff2959c8f8e8..f9445915c6c26 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -423,6 +423,82 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux
> *aux,
> }
> EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
>
> +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
> + u8 dpcd[DP_RECEIVER_CAP_SIZE])
> +{
> + u8 dpcd_ext[6];
> + int ret;
> +
> + /*
> + * Prior to DP1.3 the bit represented by
> + * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
> + * If it is set DP_DPCD_REV at h could be at a value less than
> + * the true capability of the panel. The only way to check is to
> + * then compare h and 2200h.
> + */
> + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
> + return 0;
> +
> + ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, _ext,
> +sizeof(dpcd_ext));
> + if (ret != sizeof(dpcd_ext))
> + return -EIO;
> +
> + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
> + DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev
> (%d > %d)\n",
> + aux->name, dpcd[DP_DPCD_REV],
> + dpcd_ext[DP_DPCD_REV]);
Might be a good opportunity to convert all of these to drm_dbg_dp()?
> + return 0;
> + }
> +
> + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
> + return 0;
> +
> + DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
> + aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
> +
> + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
> +
> + return 0;
> +}
> +
> +/**
> + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
> + * available
> + * @aux: DisplayPort AUX channel
> + * @dpcd: Buffer to store the resulting DPCD in
> + *
> + * Attempts to read the base DPCD caps for @aux. Additionally, this function
> + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
> + * present.
> + *
> + * Returns: %0 if the DPCD was read successfully, negative error code
> + * otherwise.
> + */
> +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
> + u8 dpcd[DP_RECEIVER_CAP_SIZE])
> +{
> + int ret;
> +
> + ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
> + if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
> + return -EIO;
> +
> + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
> + if (ret < 0)
> + return ret;
I wonder if we should just go with the "regular" dpcd caps we just read in this
case?
Regardless of my nits,
Reviewed-by: Sean Paul
> +
> + DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
> + aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
> +
> + if (dpcd[DP_DPCD_REV] == 0)
> + ret = -EIO;
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
> +
> /**
> * drm_dp_downstream_read_info() - read DPCD downstream port info if
> available
> * @aux: DisplayPort AUX channel
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index e343965a483df..230aa0360dc61 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4449,62 +4449,6 @@ intel_dp_link_down(struct intel_encoder *encoder,
> }
> }
>
> -static void
> -intel_dp_extended_receiver_capabilities(struct intel_dp *intel_dp)
> -{
> - struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> - u8 dpcd_ext[6];
> -
> - /*
> - * Prior to DP1.3 the bit represented by
> - * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
> - * if it is set DP_DPCD_REV at h could be at a value less than
> - * the true capability of the panel. The only way to check is to
> - * then compare h and 2200h.
> - */
> - if
[Nouveau] [RFC 19/20] drm/i915/dp: Extract drm_dp_read_dpcd_caps()
Since DP 1.3, it's been possible for DP receivers to specify an
additional set of DPCD capabilities, which can take precedence over the
capabilities reported at DP_DPCD_REV.
Basically any device supporting DP is going to need to read these in an
identical manner, in particular nouveau, so let's go ahead and just move
this code out of i915 into a shared DRM DP helper that we can use in
other drivers.
Signed-off-by: Lyude Paul
---
drivers/gpu/drm/drm_dp_helper.c | 76 +
drivers/gpu/drm/i915/display/intel_dp.c | 60 +---
drivers/gpu/drm/i915/display/intel_dp.h | 1 -
drivers/gpu/drm/i915/display/intel_lspcon.c | 2 +-
include/drm/drm_dp_helper.h | 3 +
5 files changed, 82 insertions(+), 60 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 0ff2959c8f8e8..f9445915c6c26 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -423,6 +423,82 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
}
EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
+static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
+ u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+ u8 dpcd_ext[6];
+ int ret;
+
+ /*
+* Prior to DP1.3 the bit represented by
+* DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
+* If it is set DP_DPCD_REV at h could be at a value less than
+* the true capability of the panel. The only way to check is to
+* then compare h and 2200h.
+*/
+ if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+ DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
+ return 0;
+
+ ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, _ext,
+ sizeof(dpcd_ext));
+ if (ret != sizeof(dpcd_ext))
+ return -EIO;
+
+ if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
+ DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev
(%d > %d)\n",
+ aux->name, dpcd[DP_DPCD_REV],
+ dpcd_ext[DP_DPCD_REV]);
+ return 0;
+ }
+
+ if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
+ return 0;
+
+ DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
+ aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
+
+ memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
+
+ return 0;
+}
+
+/**
+ * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
+ * available
+ * @aux: DisplayPort AUX channel
+ * @dpcd: Buffer to store the resulting DPCD in
+ *
+ * Attempts to read the base DPCD caps for @aux. Additionally, this function
+ * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
+ * present.
+ *
+ * Returns: %0 if the DPCD was read successfully, negative error code
+ * otherwise.
+ */
+int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
+ u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+ int ret;
+
+ ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
+ if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
+ return -EIO;
+
+ ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
+ if (ret < 0)
+ return ret;
+
+ DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
+ aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
+
+ if (dpcd[DP_DPCD_REV] == 0)
+ ret = -EIO;
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
+
/**
* drm_dp_downstream_read_info() - read DPCD downstream port info if available
* @aux: DisplayPort AUX channel
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
b/drivers/gpu/drm/i915/display/intel_dp.c
index e343965a483df..230aa0360dc61 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4449,62 +4449,6 @@ intel_dp_link_down(struct intel_encoder *encoder,
}
}
-static void
-intel_dp_extended_receiver_capabilities(struct intel_dp *intel_dp)
-{
- struct drm_i915_private *i915 = dp_to_i915(intel_dp);
- u8 dpcd_ext[6];
-
- /*
-* Prior to DP1.3 the bit represented by
-* DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
-* if it is set DP_DPCD_REV at h could be at a value less than
-* the true capability of the panel. The only way to check is to
-* then compare h and 2200h.
-*/
- if (!(intel_dp->dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
- DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
- return;
-
- if (drm_dp_dpcd_read(_dp->aux, DP_DP13_DPCD_REV,
-_ext, sizeof(dpcd_ext)) != sizeof(dpcd_ext)) {
- drm_err(>drm,
- "DPCD failed read at extended capabilities\n");
- return;
- }
-
- if (intel_dp->dpcd[DP_DPCD_REV] >
