From: Yannick Fertre yannick.fertre@st.com
[ Upstream commit a6bd58c51ac43083f3977057a7ad668def55812f ]
Following investigations of a hardware bug, the LIE interrupt can occur while the display controller is not activated. LIE interrupt (vblank) don't have to be set if the CRTC is not enabled.
Signed-off-by: Yannick Fertre yannick.fertre@st.com Acked-by: Philippe Cornu philippe.cornu@st.com Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com Link: https://patchwork.freedesktop.org/patch/msgid/1579601650-7055-1-git-send-ema... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/stm/ltdc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 3ab4fbf8eb0d1..2526dfb77401c 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -653,9 +653,14 @@ static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = { static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc) { struct ltdc_device *ldev = crtc_to_ltdc(crtc); + struct drm_crtc_state *state = crtc->state;
DRM_DEBUG_DRIVER("\n"); - reg_set(ldev->regs, LTDC_IER, IER_LIE); + + if (state->enable) + reg_set(ldev->regs, LTDC_IER, IER_LIE); + else + return -EPERM;
return 0; }