[PATCH 1/3] drm/msm/dpu: Drop sneaky dev_pm_opp_set_rate(0)

[Konrad Dybcio <konradybcio@kernel.org>]

From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

dev_pm_opp_set_rate(0) removes the vote specified in required-opps but
does not actually park the clock, making it run without the necessary
power backing. Prevent that from happening when
_dpu_core_perf_get_core_clk_rate() returns 0.

Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
index 2ff255d7795e..fea173e37464 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
@@ -394,6 +394,10 @@ int dpu_core_perf_crtc_update(struct drm_crtc *crtc,
 
 		trace_dpu_core_perf_update_clk(kms->dev, !crtc->enabled, clk_rate);
 
+		/* If we're going offline, PM callbacks will disable the clocks instead */
+		if (!clk_rate)
+			return 0;
+
 		clk_rate = min(clk_rate, kms->perf.max_core_clk_rate);
 		ret = dev_pm_opp_set_rate(&kms->pdev->dev, clk_rate);
 		if (ret) {

-- 
2.55.0