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Commit 80ef8f9b authored by Ujwal Patel's avatar Ujwal Patel
Browse files

msm: mdss: Fix watermark level calculations for pipe updates 



Watermark (wm) levels for active pipes are calculated and set for every
surface update regardless of pipe parameters are changed or not. In the
current implementation if reserved MMBs are not changed compared previous
frame then wm levels are reset to zero. This is not a correct behaviour
and may lead to under-runs. Fix this by setting wm levels based on
allocated MMBs.

Change-Id: I857c161f7203b64411e9345553f88c48f7726ee2
Signed-off-by: default avatarUjwal Patel <ujwalp@codeaurora.org>
parent 54938e72

drivers/video/msm/mdss/mdss_mdp_pipe.c

+20 −8
Original line number Diff line number Diff line
@@ -30,7 +30,6 @@ static DEFINE_MUTEX(mdss_mdp_smp_lock); 
static DECLARE_BITMAP(mdss_mdp_smp_mmb_pool, MDSS_MDP_SMP_MMB_BLOCKS);



static int mdss_mdp_pipe_free(struct mdss_mdp_pipe *pipe);

static int __mdss_mdp_pipe_smp_mmb_is_empty(unsigned long *smp);



static inline void mdss_mdp_pipe_write(struct mdss_mdp_pipe *pipe,

				       u32 reg, u32 val)
@@ -95,11 +94,6 @@ static void mdss_mdp_smp_mmb_free(unsigned long *smp, bool write) 
	}

}



static int __mdss_mdp_pipe_smp_mmb_is_empty(unsigned long *smp)

{

	return bitmap_weight(smp, SMP_MB_CNT) == 0;

}



static void mdss_mdp_smp_set_wm_levels(struct mdss_mdp_pipe *pipe, int mb_cnt)

{

	u32 fetch_size, val, wm[3];
@@ -249,7 +243,21 @@ int mdss_mdp_smp_reserve(struct mdss_mdp_pipe *pipe) 


	return rc;

}



/*

 * mdss_mdp_smp_alloc() -- set smp mmb and and wm levels for a staged pipe

 * @pipe: pointer to a pipe

 *

 * Function amends reserved smp mmbs to allocated bitmap and ties respective

 * mmbs to their pipe fetch_ids. Based on the number of total allocated mmbs

 * for a staged pipe, it also sets the watermark levels (wm).

 *

 * This function will be called on every commit where pipe params might not

 * have changed. In such cases, we need to ensure that wm levels are not

 * wiped out. Also in some rare situations hw might have reset and wiped out

 * smp mmb programming but new smp reservation is not done. In such cases we

 * need to ensure that for a staged pipes, mmbs are set properly based on

 * allocated bitmap.

 */

static int mdss_mdp_smp_alloc(struct mdss_mdp_pipe *pipe)

{

	int i;
@@ -257,8 +265,12 @@ static int mdss_mdp_smp_alloc(struct mdss_mdp_pipe *pipe) 


	mutex_lock(&mdss_mdp_smp_lock);

	for (i = 0; i < MAX_PLANES; i++) {

		if (__mdss_mdp_pipe_smp_mmb_is_empty(pipe->smp_map[i].reserved))

		if (bitmap_empty(pipe->smp_map[i].reserved, SMP_MB_CNT)) {

			cnt += mdss_mdp_smp_mmb_set(pipe->ftch_id + i,

				pipe->smp_map[i].allocated);

			continue;

		}



		mdss_mdp_smp_mmb_amend(pipe->smp_map[i].allocated,

			pipe->smp_map[i].reserved);

		cnt += mdss_mdp_smp_mmb_set(pipe->ftch_id + i,