Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d3a18691 authored by Ingrid Gallardo's avatar Ingrid Gallardo
Browse files

msm: mdss: fix spurious wait4pingpong timeouts 



In some cases, the jiffies of the wait function can
jump between reads, leading to wrongly detected
ping pong timeouts. Prevent to fail in this scenario
by making sure that the time elapsed during the
wait is valid.

CRs-Fixed: 1048727
Change-Id: I3a1ecc89f379a90d9fdacf0baa9b6c8498bb93fb
Signed-off-by: default avatarIngrid Gallardo <ingridg@codeaurora.org>
parent 0fdb8c8e

drivers/video/fbdev/msm/mdss_mdp.h

+2 −1
Original line number Diff line number Diff line
@@ -56,7 +56,8 @@ 
#define C0_G_Y		0	/* G/luma */



/* wait for at most 2 vsync for lowest refresh rate (24hz) */

#define KOFF_TIMEOUT msecs_to_jiffies(84)

#define KOFF_TIMEOUT_MS 84

#define KOFF_TIMEOUT msecs_to_jiffies(KOFF_TIMEOUT_MS)



#define OVERFETCH_DISABLE_TOP		BIT(0)

#define OVERFETCH_DISABLE_BOTTOM	BIT(1)

drivers/video/fbdev/msm/mdss_mdp_intf_cmd.c

+21 −3
Original line number Diff line number Diff line
@@ -1835,6 +1835,26 @@ int mdss_mdp_cmd_reconfigure_splash_done(struct mdss_mdp_ctl *ctl, 
	return ret;

}



static int __mdss_mdp_wait4pingpong(struct mdss_mdp_cmd_ctx *ctx)

{

	int rc = 0;

	s64 expected_time = ktime_to_ms(ktime_get()) + KOFF_TIMEOUT_MS;

	s64 time;



	do {

		rc = wait_event_timeout(ctx->pp_waitq,

				atomic_read(&ctx->koff_cnt) == 0,

				KOFF_TIMEOUT);

		time = ktime_to_ms(ktime_get());



		MDSS_XLOG(rc, time, expected_time, atomic_read(&ctx->koff_cnt));

	/* If we timed out, counter is valid and time is less, wait again */

	} while (atomic_read(&ctx->koff_cnt) && (rc == 0) &&

			(time < expected_time));



	return rc;

}



static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg)

{

	struct mdss_mdp_cmd_ctx *ctx;
@@ -1856,9 +1876,7 @@ static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg) 
	pr_debug("%s: intf_num=%d ctx=%p koff_cnt=%d\n", __func__,

			ctl->intf_num, ctx, atomic_read(&ctx->koff_cnt));



	rc = wait_event_timeout(ctx->pp_waitq,

			atomic_read(&ctx->koff_cnt) == 0,

			KOFF_TIMEOUT);

	rc = __mdss_mdp_wait4pingpong(ctx);



	trace_mdp_cmd_wait_pingpong(ctl->num,

				atomic_read(&ctx->koff_cnt));