diff mbox series

[v5,05/15] drm/msm/dpu: decide right side per last bit

Message ID 20250118-sm8650-v6-13-hmd-deckard-mdss-quad-upstream-33-v5-5-9701a16340da@linaro.org
State Superseded
Headers show
Series drm/msm/dpu: Support quad pipe with dual-DSI | expand

Commit Message

Jun Nie Jan. 17, 2025, 4 p.m. UTC 
Currently, only one pair of mixers is supported, so a non-zero counter
value is sufficient to identify the correct mixer within that pair.
However, future implementations may involve multiple mixer pairs. With
the current implementation, all mixers within the second pair would be
incorrectly selected as right mixer. To correctly select the mixer
within a pair, test the least significant bit of the counter. If the
least significant bit is not set, select the mixer as left one;
otherwise, select the mixer as right one for all pairs.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Jessica Zhang Feb. 15, 2025, 12:29 a.m. UTC | #1 
On 1/17/2025 8:00 AM, Jun Nie wrote:
> Currently, only one pair of mixers is supported, so a non-zero counter
> value is sufficient to identify the correct mixer within that pair.
> However, future implementations may involve multiple mixer pairs. With
> the current implementation, all mixers within the second pair would be
> incorrectly selected as right mixer. To correctly select the mixer
> within a pair, test the least significant bit of the counter. If the
> least significant bit is not set, select the mixer as left one;
> otherwise, select the mixer as right one for all pairs.
> 
> Signed-off-by: Jun Nie <jun.nie@linaro.org>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>

> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 7191b1a6d41b3..41c9d3e3e3c7c 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -369,11 +369,10 @@ static void _dpu_crtc_setup_blend_cfg(struct dpu_crtc_mixer *mixer,
>   static void _dpu_crtc_program_lm_output_roi(struct drm_crtc *crtc)
>   {
>   	struct dpu_crtc_state *crtc_state;
> -	int lm_idx, lm_horiz_position;
> +	int lm_idx;
>   
>   	crtc_state = to_dpu_crtc_state(crtc->state);
>   
> -	lm_horiz_position = 0;
>   	for (lm_idx = 0; lm_idx < crtc_state->num_mixers; lm_idx++) {
>   		const struct drm_rect *lm_roi = &crtc_state->lm_bounds[lm_idx];
>   		struct dpu_hw_mixer *hw_lm = crtc_state->mixers[lm_idx].hw_lm;
> @@ -384,7 +383,7 @@ static void _dpu_crtc_program_lm_output_roi(struct drm_crtc *crtc)
>   
>   		cfg.out_width = drm_rect_width(lm_roi);
>   		cfg.out_height = drm_rect_height(lm_roi);
> -		cfg.right_mixer = lm_horiz_position++;
> +		cfg.right_mixer = lm_idx & 0x1;
>   		cfg.flags = 0;
>   		hw_lm->ops.setup_mixer_out(hw_lm, &cfg);
>   	}
> 
> -- 
> 2.34.1
>
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 7191b1a6d41b3..41c9d3e3e3c7c 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -369,11 +369,10 @@  static void _dpu_crtc_setup_blend_cfg(struct dpu_crtc_mixer *mixer,
 static void _dpu_crtc_program_lm_output_roi(struct drm_crtc *crtc)
 {
 	struct dpu_crtc_state *crtc_state;
-	int lm_idx, lm_horiz_position;
+	int lm_idx;
 
 	crtc_state = to_dpu_crtc_state(crtc->state);
 
-	lm_horiz_position = 0;
 	for (lm_idx = 0; lm_idx < crtc_state->num_mixers; lm_idx++) {
 		const struct drm_rect *lm_roi = &crtc_state->lm_bounds[lm_idx];
 		struct dpu_hw_mixer *hw_lm = crtc_state->mixers[lm_idx].hw_lm;
@@ -384,7 +383,7 @@  static void _dpu_crtc_program_lm_output_roi(struct drm_crtc *crtc)
 
 		cfg.out_width = drm_rect_width(lm_roi);
 		cfg.out_height = drm_rect_height(lm_roi);
-		cfg.right_mixer = lm_horiz_position++;
+		cfg.right_mixer = lm_idx & 0x1;
 		cfg.flags = 0;
 		hw_lm->ops.setup_mixer_out(hw_lm, &cfg);
 	}