From: Marek Vasut marex@denx.de
[ Upstream commit ebd267b2e3c25d5f93a08528b47c036569eb8744 ]
Add missing pm_runtime_get_sync() into ltdc_crtc_atomic_enable() to match pm_runtime_put_sync() in ltdc_crtc_atomic_disable(), otherwise the LTDC might suspend via runtime PM, disable clock, and then fail to resume later on.
The test which triggers it is roughly -- run qt5 application which uses eglfs platform and etnaviv, stop the application, sleep for 15 minutes, run the application again. This leads to a timeout waiting for vsync, because the LTDC has suspended, but did not resume.
Fixes: 35ab6cfbf211 ("drm/stm: support runtime power management") Signed-off-by: Marek Vasut marex@denx.de Cc: Yannick Fertré yannick.fertre@st.com Cc: Philippe Cornu philippe.cornu@st.com Cc: Benjamin Gaignard benjamin.gaignard@linaro.org Cc: Vincent Abriou vincent.abriou@st.com Cc: Maxime Coquelin mcoquelin.stm32@gmail.com Cc: Alexandre Torgue alexandre.torgue@st.com To: dri-devel@lists.freedesktop.org Cc: linux-stm32@st-md-mailman.stormreply.com Cc: linux-arm-kernel@lists.infradead.org Acked-by: Philippe Cornu philippe.cornu@st.com Tested-by: Yannick Fertre yannick.fertre@st.com Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com Link: https://patchwork.freedesktop.org/patch/msgid/20200229221649.90813-1-marex@d... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/stm/ltdc.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 3ab4fbf8eb0d1..51571f7246abf 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -424,9 +424,12 @@ static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc, struct drm_crtc_state *old_state) { struct ltdc_device *ldev = crtc_to_ltdc(crtc); + struct drm_device *ddev = crtc->dev;
DRM_DEBUG_DRIVER("\n");
+ pm_runtime_get_sync(ddev->dev); + /* Sets the background color value */ reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);