Re: [PATCH v3 12/38] drm/msm/dp: introduce max_streams for DP controller MST support

[Yongxing Mou <yongxing.mou@oss.qualcomm.com>]

On 3/30/2026 6:35 PM, Dmitry Baryshkov wrote:
> On Mon, Mar 30, 2026 at 05:57:13PM +0800, Yongxing Mou wrote:
>>
>>
>> On 8/26/2025 1:42 AM, Dmitry Baryshkov wrote:
>>> On Mon, Aug 25, 2025 at 10:15:58PM +0800, Yongxing Mou wrote:
>>>> From: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>>>
>>>> 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?
>>>
>> Each DP controller have it own msm_dp_desc ...
> 
> Why do you need to mention it?
> 
Sorry, I may have misunderstood your “How?”. Could you please clarify 
what aspect you are referring to (commit message wording vs. the actual 
implementation)?
>>>>
>>>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>>> Signed-off-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com>
>>>> ---
>>>>    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?
>>>
>> If remove mst_supported, condition "mst_streams > 1" will appear in multiple
>> places.
> 
> And so what? If you want, extract the function, but don't add
> duplicating data.
> 
Got it. will remove this "mst_supported".
>>>>    	struct drm_device *drm_dev;
>