drm/msm: dpu: Simplify frame_done watchdog timeout calculation

Instead of setting the timeout and then immediately reading it back
(along with the hand-rolled msecs_to_jiffies calculation), just
calculate it once and set it in both places at the same time.

Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190128204306.95076-2-sean@poorly.run
Signed-off-by: Rob Clark <robdclark@chromium.org>

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 3a71469..107abd4 100644 (file)
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1788,6 +1788,7 @@ void dpu_encoder_kickoff(struct drm_encoder *drm_enc, bool async)
 {
        struct dpu_encoder_virt *dpu_enc;
        struct dpu_encoder_phys *phys;
+       unsigned long timeout_ms;
        ktime_t wakeup_time;
        unsigned int i;
 
@@ -1800,11 +1801,12 @@ void dpu_encoder_kickoff(struct drm_encoder *drm_enc, bool async)
 
        trace_dpu_enc_kickoff(DRMID(drm_enc));
 
-       atomic_set(&dpu_enc->frame_done_timeout,
-                       DPU_FRAME_DONE_TIMEOUT * 1000 /
-                       drm_mode_vrefresh(&drm_enc->crtc->state->adjusted_mode));
-       mod_timer(&dpu_enc->frame_done_timer, jiffies +
-               ((atomic_read(&dpu_enc->frame_done_timeout) * HZ) / 1000));
+       timeout_ms = DPU_FRAME_DONE_TIMEOUT * 1000 /
+               drm_mode_vrefresh(&drm_enc->crtc->state->adjusted_mode);
+
+       atomic_set(&dpu_enc->frame_done_timeout, timeout_ms);
+       mod_timer(&dpu_enc->frame_done_timer,
+                 jiffies + msecs_to_jiffies(timeout_ms));
 
        /* All phys encs are ready to go, trigger the kickoff */
        _dpu_encoder_kickoff_phys(dpu_enc, async);