Hey Lyude,
On 2022-08-05 17:17, Lyude Paul wrote:
lgtm!
Any chance you can apply this to drm-misc-next?
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
On Fri, 2022-08-05 at 17:13 -0400, Hamza Mahfooz wrote:
Currently, there is no way to identify if DSC pass-through can be
enabled and what aux DSC pass-through requests ought to be sent to. So,
add a variable to struct drm_dp_mst_port that keeps track of the
aforementioned information.
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
---
v2: define DP_DSC_PASSTHROUGH_IS_SUPPORTED
---
drivers/gpu/drm/display/drm_dp_mst_topology.c | 4 +++-
include/drm/display/drm_dp.h | 1 +
include/drm/display/drm_dp_mst_helper.h | 3 +++
3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 67b3b9697da7..71915afd9892 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -5921,8 +5921,10 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
/* Enpoint decompression with DP-to-DP peer device */
if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
(endpoint_fec & DP_FEC_CAPABLE) &&
- (upstream_dsc & 0x2) /* DSC passthrough */)
+ (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) {
+ port->passthrough_aux = &immediate_upstream_port->aux;
return &port->aux;
+ }
/* Virtual DPCD decompression with DP-to-DP peer device */
return &immediate_upstream_port->aux;
diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h
index 9e3aff7e68bb..4d0abe4c7ea9 100644
--- a/include/drm/display/drm_dp.h
+++ b/include/drm/display/drm_dp.h
@@ -239,6 +239,7 @@
#define DP_DSC_SUPPORT 0x060 /* DP 1.4 */
# define DP_DSC_DECOMPRESSION_IS_SUPPORTED (1 << 0)
+# define DP_DSC_PASSTHROUGH_IS_SUPPORTED (1 << 1)
#define DP_DSC_REV 0x061
# define DP_DSC_MAJOR_MASK (0xf << 0)
diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h
index 10adec068b7f..4a39c95f8afd 100644
--- a/include/drm/display/drm_dp_mst_helper.h
+++ b/include/drm/display/drm_dp_mst_helper.h
@@ -86,6 +86,8 @@ struct drm_dp_vcpi {
* @next: link to next port on this branch device
* @aux: i2c aux transport to talk to device connected to this port, protected
* by &drm_dp_mst_topology_mgr.base.lock.
+ * @passthrough_aux: parent aux to which DSC pass-through requests should be
+ * sent, only set if DSC pass-through is possible.
* @parent: branch device parent of this port
* @vcpi: Virtual Channel Payload info for this port.
* @connector: DRM connector this port is connected to. Protected by
@@ -140,6 +142,7 @@ struct drm_dp_mst_port {
*/
struct drm_dp_mst_branch *mstb;
struct drm_dp_aux aux; /* i2c bus for this port? */
+ struct drm_dp_aux *passthrough_aux;
struct drm_dp_mst_branch *parent;
struct drm_dp_vcpi vcpi;
--
Hamza
