drm/msm/sde: increase hw reset wait to 2ms
The existing polling loop that waits for ctl hardware
resets can time out in as little as 400us. This patch
increases the polling loop to 2ms, and makes use of
ktime to provide a more deterministic wait interval.
Change-Id: I34f640e193ba0a2e40eaf6b826ea61a47493a0dc
Signed-off-by: Clarence Ip <cip@codeaurora.org>
diff --git a/drivers/gpu/drm/msm/sde/sde_hw_ctl.c b/drivers/gpu/drm/msm/sde/sde_hw_ctl.c
index 0b3432b..d89c6a9 100644
--- a/drivers/gpu/drm/msm/sde/sde_hw_ctl.c
+++ b/drivers/gpu/drm/msm/sde/sde_hw_ctl.c
@@ -38,7 +38,7 @@
#define CTL_MIXER_BORDER_OUT BIT(24)
#define CTL_FLUSH_MASK_CTL BIT(17)
-#define SDE_REG_RESET_TIMEOUT_COUNT 20
+#define SDE_REG_RESET_TIMEOUT_US 2000
static struct sde_ctl_cfg *_ctl_offset(enum sde_ctl ctl,
struct sde_mdss_cfg *m,
@@ -294,14 +294,13 @@
return 0;
}
-static u32 sde_hw_ctl_poll_reset_status(struct sde_hw_ctl *ctx, u32 count)
+static u32 sde_hw_ctl_poll_reset_status(struct sde_hw_ctl *ctx, u32 timeout_us)
{
struct sde_hw_blk_reg_map *c = &ctx->hw;
+ ktime_t timeout;
u32 status;
- /* protect to do at least one iteration */
- if (!count)
- count = 1;
+ timeout = ktime_add_us(ktime_get(), timeout_us);
/*
* it takes around 30us to have mdp finish resetting its ctl path
@@ -309,10 +308,10 @@
*/
do {
status = SDE_REG_READ(c, CTL_SW_RESET);
- status &= 0x01;
+ status &= 0x1;
if (status)
usleep_range(20, 50);
- } while (status && --count > 0);
+ } while (status && ktime_compare_safe(ktime_get(), timeout) < 0);
return status;
}
@@ -323,7 +322,7 @@
pr_debug("issuing hw ctl reset for ctl:%d\n", ctx->idx);
SDE_REG_WRITE(c, CTL_SW_RESET, 0x1);
- if (sde_hw_ctl_poll_reset_status(ctx, SDE_REG_RESET_TIMEOUT_COUNT))
+ if (sde_hw_ctl_poll_reset_status(ctx, SDE_REG_RESET_TIMEOUT_US))
return -EINVAL;
return 0;
@@ -340,7 +339,7 @@
return 0;
pr_debug("hw ctl reset is set for ctl:%d\n", ctx->idx);
- if (sde_hw_ctl_poll_reset_status(ctx, SDE_REG_RESET_TIMEOUT_COUNT)) {
+ if (sde_hw_ctl_poll_reset_status(ctx, SDE_REG_RESET_TIMEOUT_US)) {
pr_err("hw recovery is not complete for ctl:%d\n", ctx->idx);
return -EINVAL;
}