From 5cc99c07c765b8d4ad4fe445a73021ed8210c67c Mon Sep 17 00:00:00 2001
From: Yannick Fertre <yannick.fertre@st.com>
Date: Tue, 21 Jan 2020 11:14:10 +0100
Subject: drm/stm: ltdc: check crtc state before enabling LIE
Git-commit: a6bd58c51ac43083f3977057a7ad668def55812f
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
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-email-yannick.fertre@st.com
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
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 58092b0b8885..8750ee831bea 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -648,9 +648,14 @@ 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;
}
--
2.28.0