diff mbox series

[3/5] drm/msm/dpu: Check mode against PINGPONG or DSC max width

Message ID 20250514-max-mixer-width-v1-3-c8ba0d9bb858@oss.qualcomm.com
State New
Headers show
Series drm/msm/dpu: Drop max_mixer_width and MAX_HDISPLAY_SPLIT | expand

Commit Message

Jessica Zhang May 14, 2025, 11:52 p.m. UTC 
Validate requested mode and topology based on the PINGPONG or DSC encoder
max width. In addition, drop MAX_HDISPLAY_SPLIT and base LM reservation
off of PINGPONG or DSC encoder max width

As noted in the patch, while DPU 8.x+ supports a max linewidth of 8960
for PINGPONG_0, there is some additional logic that needs to be added to
the resource manager to specifically try and reserve PINGPONG_0 for
modes that are greater than 5k.

Since this is out of the scope of this series, add a helper that will
get the overall minimum PINGPONG max linewidth for a given chipset.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 46 +++++++++++++++++++++++++++-----
 1 file changed, 39 insertions(+), 7 deletions(-)

Comments

Jessica Zhang May 16, 2025, 12:39 a.m. UTC | #1 
On 5/14/2025 5:28 PM, Dmitry Baryshkov wrote:
> On Wed, May 14, 2025 at 04:52:31PM -0700, Jessica Zhang wrote:
>> Validate requested mode and topology based on the PINGPONG or DSC encoder
>> max width. In addition, drop MAX_HDISPLAY_SPLIT and base LM reservation
>> off of PINGPONG or DSC encoder max width
> 
> Separate commit for num_lm, please.

Hi Dmitry,

Ack.

> 
>>
>> As noted in the patch, while DPU 8.x+ supports a max linewidth of 8960
>> for PINGPONG_0, there is some additional logic that needs to be added to
>> the resource manager to specifically try and reserve PINGPONG_0 for
>> modes that are greater than 5k.
>>
>> Since this is out of the scope of this series, add a helper that will
>> get the overall minimum PINGPONG max linewidth for a given chipset.
>>
>> Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 46 +++++++++++++++++++++++++++-----
>>   1 file changed, 39 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> index 0714936d8835..6131d071b051 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> @@ -723,6 +723,31 @@ void dpu_crtc_complete_commit(struct drm_crtc *crtc)
>>   	_dpu_crtc_complete_flip(crtc);
>>   }
>>   
>> +static int msm_display_get_max_pingpong_width(struct dpu_kms *dpu_kms)
>> +{
>> +	const struct dpu_pingpong_cfg *pingpong;
>> +	u32 max_pingpong_width = dpu_kms->catalog->pingpong[0].max_linewidth;
>> +
>> +	/*
>> +	 * Find the smallest overall PINGPONG max_linewidth in the catalog since
>> +	 * max_linewidth can differ between PINGPONGs even within the same
>> +	 * chipset.
>> +	 *
>> +	 * Note: While, for DPU 8.x+, PINGPONG_0 can technically support up to
>> +	 * 8k resolutions, this requires reworking the RM to try to reserve
>> +	 * PINGPONG_0 for modes greater than 5k.
>> +	 *
>> +	 * Once this additional logic is implemented, we can drop this helper
>> +	 * and use the reserved PINGPONG's max_linewidth
>> +	 */
>> +	for (int i = 1; i < dpu_kms->catalog->pingpong_count; i++) {
>> +		pingpong = &dpu_kms->catalog->pingpong[i];
>> +		max_pingpong_width = min(max_pingpong_width, pingpong->max_linewidth);
>> +	}
> 
> Since we are skipping PINGPONG_0, wouldn't it be enough to return
> max_linewidth of PP_1 ?

I don't think we're skipping PINGPONG_0 here since `u32 
max_pingpong_width = dpu_kms->catalog->pingpong[0].max_linewidth;` at 
the top of the function.

> 
> I think, it would be easier to follow .max_dsc_encoder_width and store
> .max_pingpong_linewidth in dpu_caps (and later add special
> .max_pp0_linewidth).

Ack. I think my only concern for this is that max_pp0_linewidth won't be 
set for all chipsets. But if you're fine with that I'll go ahead and 
make this change.

Thanks,

Jessica Zhang

> 
>> +
>> +	return max_pingpong_width;
>> +}
>> +
>>   static int _dpu_crtc_check_and_setup_lm_bounds(struct drm_crtc *crtc,
>>   		struct drm_crtc_state *state)
>>   {
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 0714936d8835..6131d071b051 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -723,6 +723,31 @@  void dpu_crtc_complete_commit(struct drm_crtc *crtc)
 	_dpu_crtc_complete_flip(crtc);
 }
 
+static int msm_display_get_max_pingpong_width(struct dpu_kms *dpu_kms)
+{
+	const struct dpu_pingpong_cfg *pingpong;
+	u32 max_pingpong_width = dpu_kms->catalog->pingpong[0].max_linewidth;
+
+	/*
+	 * Find the smallest overall PINGPONG max_linewidth in the catalog since
+	 * max_linewidth can differ between PINGPONGs even within the same
+	 * chipset.
+	 *
+	 * Note: While, for DPU 8.x+, PINGPONG_0 can technically support up to
+	 * 8k resolutions, this requires reworking the RM to try to reserve
+	 * PINGPONG_0 for modes greater than 5k.
+	 *
+	 * Once this additional logic is implemented, we can drop this helper
+	 * and use the reserved PINGPONG's max_linewidth
+	 */
+	for (int i = 1; i < dpu_kms->catalog->pingpong_count; i++) {
+		pingpong = &dpu_kms->catalog->pingpong[i];
+		max_pingpong_width = min(max_pingpong_width, pingpong->max_linewidth);
+	}
+
+	return max_pingpong_width;
+}
+
 static int _dpu_crtc_check_and_setup_lm_bounds(struct drm_crtc *crtc,
 		struct drm_crtc_state *state)
 {
@@ -730,13 +755,14 @@  static int _dpu_crtc_check_and_setup_lm_bounds(struct drm_crtc *crtc,
 	struct drm_display_mode *adj_mode = &state->adjusted_mode;
 	u32 crtc_split_width = adj_mode->hdisplay / cstate->num_mixers;
 	struct dpu_kms *dpu_kms = _dpu_crtc_get_kms(crtc);
+	int max_pingpong_width = msm_display_get_max_pingpong_width(dpu_kms);
 	int i;
 
 	/* if we cannot merge 2 LMs (no 3d mux) better to fail earlier
 	 * before even checking the width after the split
 	 */
 	if (!dpu_kms->catalog->caps->has_3d_merge &&
-	    adj_mode->hdisplay > dpu_kms->catalog->caps->max_mixer_width)
+	    adj_mode->hdisplay > max_pingpong_width)
 		return -E2BIG;
 
 	for (i = 0; i < cstate->num_mixers; i++) {
@@ -748,7 +774,7 @@  static int _dpu_crtc_check_and_setup_lm_bounds(struct drm_crtc *crtc,
 
 		trace_dpu_crtc_setup_lm_bounds(DRMID(crtc), i, r);
 
-		if (drm_rect_width(r) > dpu_kms->catalog->caps->max_mixer_width)
+		if (drm_rect_width(r) > max_pingpong_width)
 			return -E2BIG;
 	}
 
@@ -1279,7 +1305,6 @@  static int dpu_crtc_reassign_planes(struct drm_crtc *crtc, struct drm_crtc_state
 }
 
 #define MAX_CHANNELS_PER_CRTC 2
-#define MAX_HDISPLAY_SPLIT 1080
 
 static struct msm_display_topology dpu_crtc_get_topology(
 		struct drm_crtc *crtc,
@@ -1289,12 +1314,18 @@  static struct msm_display_topology dpu_crtc_get_topology(
 	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
 	struct msm_display_topology topology = {0};
 	struct drm_encoder *drm_enc;
+	const struct dpu_caps *caps = dpu_kms->catalog->caps;
+	u32 max_hdisplay_split;
 
 	drm_for_each_encoder_mask(drm_enc, crtc->dev, crtc_state->encoder_mask)
 		dpu_encoder_update_topology(drm_enc, &topology, crtc_state->state,
 					    &crtc_state->adjusted_mode);
 
 	topology.cwb_enabled = drm_crtc_in_clone_mode(crtc_state);
+	max_hdisplay_split = msm_display_get_max_pingpong_width(dpu_kms);
+
+	if (topology.num_dsc > 0 && caps->max_dsc_encoder_width > 0)
+		max_hdisplay_split = min(max_hdisplay_split, caps->max_dsc_encoder_width);
 
 	/*
 	 * Datapath topology selection
@@ -1315,7 +1346,7 @@  static struct msm_display_topology dpu_crtc_get_topology(
 	 * count both the WB and real-time phys encoders.
 	 *
 	 * For non-DSC CWB usecases, have the num_lm be decided by the
-	 * (mode->hdisplay > MAX_HDISPLAY_SPLIT) check.
+	 * (mode->hdisplay > max_hdisplay_split) check.
 	 */
 
 	if (topology.num_intf == 2 && !topology.cwb_enabled)
@@ -1323,7 +1354,7 @@  static struct msm_display_topology dpu_crtc_get_topology(
 	else if (topology.num_dsc == 2)
 		topology.num_lm = 2;
 	else if (dpu_kms->catalog->caps->has_3d_merge)
-		topology.num_lm = (mode->hdisplay > MAX_HDISPLAY_SPLIT) ? 2 : 1;
+		topology.num_lm = (mode->hdisplay > max_hdisplay_split) ? 2 : 1;
 	else
 		topology.num_lm = 1;
 
@@ -1501,18 +1532,19 @@  static enum drm_mode_status dpu_crtc_mode_valid(struct drm_crtc *crtc,
 						const struct drm_display_mode *mode)
 {
 	struct dpu_kms *dpu_kms = _dpu_crtc_get_kms(crtc);
+	int max_pingpong_width = msm_display_get_max_pingpong_width(dpu_kms);
 
 	/* if there is no 3d_mux block we cannot merge LMs so we cannot
 	 * split the large layer into 2 LMs, filter out such modes
 	 */
 	if (!dpu_kms->catalog->caps->has_3d_merge &&
-	    mode->hdisplay > dpu_kms->catalog->caps->max_mixer_width)
+	    mode->hdisplay > max_pingpong_width)
 		return MODE_BAD_HVALUE;
 	/*
 	 * max crtc width is equal to the max mixer width * 2 and max height is 4K
 	 */
 	return drm_mode_validate_size(mode,
-				      2 * dpu_kms->catalog->caps->max_mixer_width,
+				      2 * max_pingpong_width,
 				      4096);
 }