From: "Jason-JH.Lin" <jason-jh.lin@xxxxxxxxxxxx>
In mtk_crtc_ddp_config(), mtk_crtc will use some configuration flags to
generate instructions to cmdq_handle, such as:
state->pending_config
mtk_crtc->pending_planes
plane_state->pending.config
mtk_crtc->pending_async_planes
plane_state->pending.async_config
These configuration flags may be set to false when a GCE IRQ comes calling
ddp_cmdq_cb(). This may result in missing prepare instructions,
especially if mtk_crtc_update_config() with the flase need_vblank (no need
to wait for vblank) cases.
Therefore, the mtk_crtc->config_updating flag is set at the beginning of
mtk_crtc_update_config() to ensure that these configuration flags won't be
changed when the mtk_crtc_ddp_config() is preparing instructions.
But somehow the ddp_cmdq_cb() didn't use the mtk_crtc->config_updating
flag to prevent those pending config flags from being cleared.
To avoid missing the configuration when generating the config instruction,
the config_updating flag should be added into ddp_cmdq_cb() and be
protected with spin_lock.
Fixes: 7f82d9c43879 ("drm/mediatek: Clear pending flag when cmdq packet is done")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
---
Change in v2:
Add spin_lock protection for config_updating flag.
---
drivers/gpu/drm/mediatek/mtk_crtc.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
index 6f34f573e127..b752c0b46383 100644
--- a/drivers/gpu/drm/mediatek/mtk_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
@@ -69,6 +69,8 @@ struct mtk_crtc {
/* lock for display hardware access */
struct mutex hw_lock;
bool config_updating;
+ /* lock for config_updating to cmd buffer */
+ spinlock_t config_lock;
};
struct mtk_crtc_state {
@@ -107,10 +109,13 @@ static void mtk_crtc_finish_page_flip(struct mtk_crtc *mtk_crtc)
static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc)
{
drm_crtc_handle_vblank(&mtk_crtc->base);
+
+ spin_lock(&mtk_crtc->config_lock);
if (!mtk_crtc->config_updating && mtk_crtc->pending_needs_vblank) {
mtk_crtc_finish_page_flip(mtk_crtc);
mtk_crtc->pending_needs_vblank = false;
}
+ spin_unlock(&mtk_crtc->config_lock);
}
#if IS_REACHABLE(CONFIG_MTK_CMDQ)
@@ -314,6 +319,13 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
state = to_mtk_crtc_state(mtk_crtc->base.state);
+ spin_lock(&mtk_crtc->config_lock);
+
+ if (mtk_crtc->config_updating) {
+ spin_unlock(&mtk_crtc->config_lock);
+ goto ddp_cmdq_cb_out;
+ }
+
state->pending_config = false;
if (mtk_crtc->pending_planes) {
@@ -340,6 +352,10 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
mtk_crtc->pending_async_planes = false;
}
+ spin_unlock(&mtk_crtc->config_lock);
+
+ddp_cmdq_cb_out:
+
mtk_crtc->cmdq_vblank_cnt = 0;
wake_up(&mtk_crtc->cb_blocking_queue);
}
@@ -571,7 +587,11 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank)
int i;
mutex_lock(&mtk_crtc->hw_lock);
+
+ spin_lock(&mtk_crtc->config_lock);
mtk_crtc->config_updating = true;
+ spin_unlock(&mtk_crtc->config_lock);
+
if (needs_vblank)
mtk_crtc->pending_needs_vblank = true;
@@ -625,7 +645,10 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank)
mbox_client_txdone(mtk_crtc->cmdq_client.chan, 0);
}
#endif
+ spin_lock(&mtk_crtc->config_lock);
mtk_crtc->config_updating = false;
+ spin_unlock(&mtk_crtc->config_lock);
+
mutex_unlock(&mtk_crtc->hw_lock);
}
@@ -1068,6 +1091,7 @@ int mtk_crtc_create(struct drm_device *drm_dev, const unsigned int *path,
drm_mode_crtc_set_gamma_size(&mtk_crtc->base, gamma_lut_size);
drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, has_ctm, gamma_lut_size);
mutex_init(&mtk_crtc->hw_lock);
+ spin_lock_init(&mtk_crtc->config_lock);
#if IS_REACHABLE(CONFIG_MTK_CMDQ)
i = priv->mbox_index++;
---
base-commit: 469f1bad3c1c6e268059f78c0eec7e9552b3894c
change-id: 20240819-drm-fixup-0819-f51e2d37fcd7
Best regards,
--
Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
