[PATCH v3 1/6] drm/tilcdc: Take crtc modeset lock while updating the crtc clock rate

[Jyri Sarha]

Take crtc modeset lock while updating the crtc clock rate. To avoid a
race in tilcdc_crtc_update_clk(), we do not want crtc mode to change
while we update crtc clock.

Signed-off-by: Jyri Sarha <jsarha at ti.com>
---
 drivers/gpu/drm/tilcdc/tilcdc_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index f8892e9..b1ac61e 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -184,10 +184,13 @@ static int cpufreq_transition(struct notifier_block *nb,
 {
 	struct tilcdc_drm_private *priv = container_of(nb,
 			struct tilcdc_drm_private, freq_transition);
+
 	if (val == CPUFREQ_POSTCHANGE) {
 		if (priv->lcd_fck_rate != clk_get_rate(priv->clk)) {
+			drm_modeset_lock_crtc(priv->crtc, NULL);
 			priv->lcd_fck_rate = clk_get_rate(priv->clk);
 			tilcdc_crtc_update_clk(priv->crtc);
+			drm_modeset_unlock_crtc(priv->crtc);
 		}
 	}
 
-- 
1.9.1