* Re: [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write
@ 2024-01-30 7:56 Lin, Charlton
2024-01-30 14:01 ` Ville Syrjälä
0 siblings, 1 reply; 4+ messages in thread
From: Lin, Charlton @ 2024-01-30 7:56 UTC (permalink / raw)
To: intel-gfx@lists.freedesktop.org
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On 1/27/2024 12:06 PM, Arun R Murthy wrote:
> With DP2.1, multistream packetization and the underneth MST protocol
> will be required for SST. So check for MSTM_CAP to see if MST is really
> required and skip the MSTM_CTRL write so that we ensure that only the
> underneth protocol and the multistream packetization will be enabled and
> sink will not be confused by a corresponding dpcd write.
>
> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> ---
> drivers/gpu/drm/display/drm_dp_mst_topology.c | 26 +++++++++++--------
> 1 file changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> index 8ca01a6bf645..22d81732a978 100644
> --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> @@ -3666,10 +3666,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
> mgr->mst_primary = mstb;
> drm_dp_mst_topology_get_mstb(mgr->mst_primary);
>
> - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> - DP_MST_EN |
> - DP_UP_REQ_EN |
> - DP_UPSTREAM_IS_SRC);
> + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> + DP_MST_EN |
> + DP_UP_REQ_EN |
> + DP_UPSTREAM_IS_SRC);
> if (ret < 0)
> goto out_unlock;
>
> @@ -3684,7 +3685,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
> mstb = mgr->mst_primary;
> mgr->mst_primary = NULL;
> /* this can fail if the device is gone */
> - drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
> + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
> ret = 0;
> mgr->payload_id_table_cleared = false;
>
> @@ -3724,8 +3726,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
> void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
> {
> mutex_lock(&mgr->lock);
> - drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> - DP_MST_EN | DP_UPSTREAM_IS_SRC);
> + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> + DP_MST_EN | DP_UPSTREAM_IS_SRC);
> mutex_unlock(&mgr->lock);
> flush_work(&mgr->up_req_work);
> flush_work(&mgr->work);
> @@ -3773,10 +3776,11 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
> goto out_fail;
> }
>
> - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> - DP_MST_EN |
> - DP_UP_REQ_EN |
> - DP_UPSTREAM_IS_SRC);
> + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
This did not compile in Chrome dev environemnt due to uninitialized variable ret.
> + DP_MST_EN |
> + DP_UP_REQ_EN |
> + DP_UPSTREAM_IS_SRC);
> if (ret < 0) {
> drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
> goto out_fail;
Tested-by: Charlton Lin <charlton.lin@intel.com>
Regards,
Charlton Lin
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write
2024-01-30 7:56 [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Lin, Charlton
@ 2024-01-30 14:01 ` Ville Syrjälä
0 siblings, 0 replies; 4+ messages in thread
From: Ville Syrjälä @ 2024-01-30 14:01 UTC (permalink / raw)
To: 20240127063627.1369883-1-arun.r.murthy@intel.com
Cc: intel-gfx@lists.freedesktop.org
On Tue, Jan 30, 2024 at 07:56:26AM +0000, Lin, Charlton wrote:
> On 1/27/2024 12:06 PM, Arun R Murthy wrote:
> > With DP2.1, multistream packetization and the underneth MST protocol
> > will be required for SST. So check for MSTM_CAP to see if MST is really
> > required and skip the MSTM_CTRL write so that we ensure that only the
> > underneth protocol and the multistream packetization will be enabled and
> > sink will not be confused by a corresponding dpcd write.
> >
> > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> > ---
> > drivers/gpu/drm/display/drm_dp_mst_topology.c | 26 +++++++++++--------
> > 1 file changed, 15 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > index 8ca01a6bf645..22d81732a978 100644
> > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > @@ -3666,10 +3666,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
> > mgr->mst_primary = mstb;
> > drm_dp_mst_topology_get_mstb(mgr->mst_primary);
> >
> > - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> > - DP_MST_EN |
> > - DP_UP_REQ_EN |
> > - DP_UPSTREAM_IS_SRC);
> > + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> > + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> > + DP_MST_EN |
> > + DP_UP_REQ_EN |
> > + DP_UPSTREAM_IS_SRC);
> > if (ret < 0)
> > goto out_unlock;
> >
> > @@ -3684,7 +3685,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
> > mstb = mgr->mst_primary;
> > mgr->mst_primary = NULL;
> > /* this can fail if the device is gone */
> > - drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
> > + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> > + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
> > ret = 0;
> > mgr->payload_id_table_cleared = false;
> >
> > @@ -3724,8 +3726,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
> > void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
> > {
> > mutex_lock(&mgr->lock);
> > - drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> > - DP_MST_EN | DP_UPSTREAM_IS_SRC);
> > + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> > + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> > + DP_MST_EN | DP_UPSTREAM_IS_SRC);
> > mutex_unlock(&mgr->lock);
> > flush_work(&mgr->up_req_work);
> > flush_work(&mgr->work);
> > @@ -3773,10 +3776,11 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
> > goto out_fail;
> > }
> >
> > - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> > - DP_MST_EN |
> > - DP_UP_REQ_EN |
> > - DP_UPSTREAM_IS_SRC);
> > + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
> > + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
>
> This did not compile in Chrome dev environemnt due to uninitialized variable ret.
>
> > + DP_MST_EN |
> > + DP_UP_REQ_EN |
> > + DP_UPSTREAM_IS_SRC);
> > if (ret < 0) {
> > drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
> > goto out_fail;
>
> Tested-by: Charlton Lin <charlton.lin@intel.com>
The mst code does the whole toplogy discovery over sideband,
so if we don't enable that we should not even get a connector
registered. How is anything at all working with this?
--
Ville Syrjälä
Intel
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write
@ 2024-01-27 6:36 ` Arun R Murthy
0 siblings, 0 replies; 4+ messages in thread
From: Arun R Murthy @ 2024-01-27 6:36 UTC (permalink / raw)
To: dri-devel, intel-gfx; +Cc: jani.nikula
With DP2.1, multistream packetization and the underneth MST protocol
will be required for SST. So check for MSTM_CAP to see if MST is really
required and skip the MSTM_CTRL write so that we ensure that only the
underneth protocol and the multistream packetization will be enabled and
sink will not be confused by a corresponding dpcd write.
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
drivers/gpu/drm/display/drm_dp_mst_topology.c | 26 +++++++++++--------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 8ca01a6bf645..22d81732a978 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -3666,10 +3666,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
mgr->mst_primary = mstb;
drm_dp_mst_topology_get_mstb(mgr->mst_primary);
- ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN |
- DP_UP_REQ_EN |
- DP_UPSTREAM_IS_SRC);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN |
+ DP_UP_REQ_EN |
+ DP_UPSTREAM_IS_SRC);
if (ret < 0)
goto out_unlock;
@@ -3684,7 +3685,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
mstb = mgr->mst_primary;
mgr->mst_primary = NULL;
/* this can fail if the device is gone */
- drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
ret = 0;
mgr->payload_id_table_cleared = false;
@@ -3724,8 +3726,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->lock);
- drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN | DP_UPSTREAM_IS_SRC);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN | DP_UPSTREAM_IS_SRC);
mutex_unlock(&mgr->lock);
flush_work(&mgr->up_req_work);
flush_work(&mgr->work);
@@ -3773,10 +3776,11 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
goto out_fail;
}
- ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN |
- DP_UP_REQ_EN |
- DP_UPSTREAM_IS_SRC);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN |
+ DP_UP_REQ_EN |
+ DP_UPSTREAM_IS_SRC);
if (ret < 0) {
drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
goto out_fail;
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write
@ 2024-01-27 6:36 ` Arun R Murthy
0 siblings, 0 replies; 4+ messages in thread
From: Arun R Murthy @ 2024-01-27 6:36 UTC (permalink / raw)
To: dri-devel, intel-gfx; +Cc: jani.nikula, Arun R Murthy
With DP2.1, multistream packetization and the underneth MST protocol
will be required for SST. So check for MSTM_CAP to see if MST is really
required and skip the MSTM_CTRL write so that we ensure that only the
underneth protocol and the multistream packetization will be enabled and
sink will not be confused by a corresponding dpcd write.
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
drivers/gpu/drm/display/drm_dp_mst_topology.c | 26 +++++++++++--------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 8ca01a6bf645..22d81732a978 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -3666,10 +3666,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
mgr->mst_primary = mstb;
drm_dp_mst_topology_get_mstb(mgr->mst_primary);
- ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN |
- DP_UP_REQ_EN |
- DP_UPSTREAM_IS_SRC);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN |
+ DP_UP_REQ_EN |
+ DP_UPSTREAM_IS_SRC);
if (ret < 0)
goto out_unlock;
@@ -3684,7 +3685,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
mstb = mgr->mst_primary;
mgr->mst_primary = NULL;
/* this can fail if the device is gone */
- drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
ret = 0;
mgr->payload_id_table_cleared = false;
@@ -3724,8 +3726,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->lock);
- drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN | DP_UPSTREAM_IS_SRC);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN | DP_UPSTREAM_IS_SRC);
mutex_unlock(&mgr->lock);
flush_work(&mgr->up_req_work);
flush_work(&mgr->work);
@@ -3773,10 +3776,11 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
goto out_fail;
}
- ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
- DP_MST_EN |
- DP_UP_REQ_EN |
- DP_UPSTREAM_IS_SRC);
+ if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd))
+ ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+ DP_MST_EN |
+ DP_UP_REQ_EN |
+ DP_UPSTREAM_IS_SRC);
if (ret < 0) {
drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
goto out_fail;
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-01-30 14:01 UTC | newest]
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2024-01-30 7:56 [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Lin, Charlton
2024-01-30 14:01 ` Ville Syrjälä
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2024-01-27 6:36 Arun R Murthy
2024-01-27 6:36 ` Arun R Murthy
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