Re: [PATCH v3 12/38] drm/msm/dp: introduce max_streams for DP controller MST support
From: Yongxing Mou
Date: Mon Mar 30 2026 - 07:32:56 EST
On 3/30/2026 6:35 PM, Dmitry Baryshkov wrote:
On Mon, Mar 30, 2026 at 05:57:13PM +0800, Yongxing Mou wrote:Sorry, I may have misunderstood your “How?”. Could you please clarify what aspect you are referring to (commit message wording vs. the actual implementation)?
On 8/26/2025 1:42 AM, Dmitry Baryshkov wrote:
On Mon, Aug 25, 2025 at 10:15:58PM +0800, Yongxing Mou wrote:Each DP controller have it own msm_dp_desc ...
From: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Introduce the `mst_streams` field in each DP controller descriptor to
specify the number of supported MST streams. Most platforms support 2 or
4 MST streams, while platforms without MST support default to a single
stream (`DEFAULT_STREAM_COUNT = 1`).
This change also accounts for platforms with asymmetric stream support,
e.g., DP0 supporting 4 streams and DP1 supporting 2.
How?
Why do you need to mention it?
Got it. will remove this "mst_supported".If remove mst_supported, condition "mst_streams > 1" will appear in multiple
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 21 +++++++++++++++++++++
drivers/gpu/drm/msm/dp/dp_display.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 78d932bceb581ee54116926506b1025bd159108f..a8477a0a180137f15cbb1401c3964636aa32626c 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -33,6 +33,7 @@ module_param(psr_enabled, bool, 0);
MODULE_PARM_DESC(psr_enabled, "enable PSR for eDP and DP displays");
#define HPD_STRING_SIZE 30
+#define DEFAULT_STREAM_COUNT 1
enum {
ISR_DISCONNECTED,
@@ -52,6 +53,7 @@ struct msm_dp_display_private {
bool core_initialized;
bool phy_initialized;
bool audio_supported;
+ bool mst_supported;
Why do we need the separate boot field here? Isn't it enough to check the max_stream?
places.
And so what? If you want, extract the function, but don't add
duplicating data.
struct drm_device *drm_dev;