From: Arun R Murthy <arun.r.murthy@intel.com> To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: jani.nikula@intel.com, Arun R Murthy <arun.r.murthy@intel.com> Subject: [PATCHv2 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Date: Wed, 31 Jan 2024 15:53:43 +0530 [thread overview] Message-ID: <20240131102344.1671929-1-arun.r.murthy@intel.com> (raw) 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 | 38 +++++++++++-------- 1 file changed, 22 insertions(+), 16 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..c5b3e51ea0c9 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -3666,12 +3666,14 @@ 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 (ret < 0) - goto out_unlock; + 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; + } /* Write reset payload */ drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f); @@ -3684,7 +3686,8 @@ 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 +3727,9 @@ 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); @@ -3773,13 +3777,15 @@ 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 (ret < 0) { - drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); - goto out_fail; + 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; + } } /* Some hubs forget their guids after they resume */ -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Arun R Murthy <arun.r.murthy@intel.com> To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: jani.nikula@intel.com Subject: [PATCHv2 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Date: Wed, 31 Jan 2024 15:53:43 +0530 [thread overview] Message-ID: <20240131102344.1671929-1-arun.r.murthy@intel.com> (raw) 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 | 38 +++++++++++-------- 1 file changed, 22 insertions(+), 16 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..c5b3e51ea0c9 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -3666,12 +3666,14 @@ 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 (ret < 0) - goto out_unlock; + 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; + } /* Write reset payload */ drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f); @@ -3684,7 +3686,8 @@ 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 +3727,9 @@ 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); @@ -3773,13 +3777,15 @@ 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 (ret < 0) { - drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); - goto out_fail; + 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; + } } /* Some hubs forget their guids after they resume */ -- 2.25.1
next reply other threads:[~2024-01-31 10:34 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-01-31 10:23 Arun R Murthy [this message] 2024-01-31 10:23 ` [PATCHv2 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Arun R Murthy 2024-01-31 10:23 ` [PATCHv2 2/2] drm/i915/display/dp: 128/132b DP-capable with SST Arun R Murthy 2024-01-31 10:23 ` Arun R Murthy 2024-02-02 15:30 ` Jani Nikula 2024-02-01 19:06 ` ✗ Fi.CI.SPARSE: warning for series starting with [PATCHv2,1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Patchwork 2024-02-02 9:17 ` ✗ Fi.CI.SPARSE: warning for series starting with [PATCHv2,1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write (rev2) Patchwork 2024-02-02 9:36 ` ✓ Fi.CI.BAT: success " Patchwork 2024-02-02 10:48 ` ✗ Fi.CI.IGT: failure " Patchwork
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