[PATCH 5.17 243/772] drm/mediatek: Add vblank register/unregister callback functions

Greg Kroah-Hartman
2022-06-07T20:52:55Z

From: Rex-BC Chen <rex-bc.chen@mediatek.com>

[ Upstream commit b74d921b900b6ce38c6247c0a1c86be9f3746493 ]

We encountered a kernel panic issue that callback data will be NULL when
it's using in ovl irq handler. There is a timing issue between
mtk_disp_ovl_irq_handler() and mtk_ovl_disable_vblank().

To resolve this issue, we use the flow to register/unregister vblank cb:
- Register callback function and callback data when crtc creates.
- Unregister callback function and callback data when crtc destroies.

With this solution, we can assure callback data will not be NULL when
vblank is disable.

Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220321072320.15019-1-rex-bc.chen@mediatek.com/
Fixes: 9b0704988b15 ("drm/mediatek: Register vblank callback function")
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Reviewed-by: jason-jh.lin <jason-jh.lin@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/mediatek/mtk_disp_drv.h | 16 +++++++-----
drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 22 ++++++++++++----
drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 20 +++++++++-----
drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 14 +++++++++-
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 4 +++
drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 29 ++++++++++++++++-----
6 files changed, 80 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index 86c3068894b1..974462831133 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
@@ -76,9 +76,11 @@ void mtk_ovl_layer_off(struct device *dev, unsigned int idx,
void mtk_ovl_start(struct device *dev);
void mtk_ovl_stop(struct device *dev);
unsigned int mtk_ovl_supported_rotations(struct device *dev);
-void mtk_ovl_enable_vblank(struct device *dev,
- void (*vblank_cb)(void *),
- void *vblank_cb_data);
+void mtk_ovl_register_vblank_cb(struct device *dev,
+ void (*vblank_cb)(void *),
+ void *vblank_cb_data);
+void mtk_ovl_unregister_vblank_cb(struct device *dev);
+void mtk_ovl_enable_vblank(struct device *dev);
void mtk_ovl_disable_vblank(struct device *dev);

void mtk_rdma_bypass_shadow(struct device *dev);
@@ -93,9 +95,11 @@ void mtk_rdma_layer_config(struct device *dev, unsigned int idx,
struct cmdq_pkt *cmdq_pkt);
void mtk_rdma_start(struct device *dev);
void mtk_rdma_stop(struct device *dev);
-void mtk_rdma_enable_vblank(struct device *dev,
- void (*vblank_cb)(void *),
- void *vblank_cb_data);
+void mtk_rdma_register_vblank_cb(struct device *dev,
+ void (*vblank_cb)(void *),
+ void *vblank_cb_data);
+void mtk_rdma_unregister_vblank_cb(struct device *dev);
+void mtk_rdma_enable_vblank(struct device *dev);
void mtk_rdma_disable_vblank(struct device *dev);

#endif
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index 2146299e5f52..1fa1bbac9f9c 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -96,14 +96,28 @@ static irqreturn_t mtk_disp_ovl_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}

-void mtk_ovl_enable_vblank(struct device *dev,
- void (*vblank_cb)(void *),
- void *vblank_cb_data)
+void mtk_ovl_register_vblank_cb(struct device *dev,
+ void (*vblank_cb)(void *),
+ void *vblank_cb_data)
{
struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);

ovl->vblank_cb = vblank_cb;
ovl->vblank_cb_data = vblank_cb_data;
+}
+
+void mtk_ovl_unregister_vblank_cb(struct device *dev)
+{
+ struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
+
+ ovl->vblank_cb = NULL;
+ ovl->vblank_cb_data = NULL;
+}
+
+void mtk_ovl_enable_vblank(struct device *dev)
+{
+ struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
+
writel(0x0, ovl->regs + DISP_REG_OVL_INTSTA);
writel_relaxed(OVL_FME_CPL_INT, ovl->regs + DISP_REG_OVL_INTEN);
}
@@ -112,8 +126,6 @@ void mtk_ovl_disable_vblank(struct device *dev)
{
struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);

- ovl->vblank_cb = NULL;
- ovl->vblank_cb_data = NULL;
writel_relaxed(0x0, ovl->regs + DISP_REG_OVL_INTEN);
}

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
index d41a3970b944..943780fc7bf6 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
@@ -94,24 +94,32 @@ static void rdma_update_bits(struct device *dev, unsigned int reg,
writel(tmp, rdma->regs + reg);
}

-void mtk_rdma_enable_vblank(struct device *dev,
- void (*vblank_cb)(void *),
- void *vblank_cb_data)
+void mtk_rdma_register_vblank_cb(struct device *dev,
+ void (*vblank_cb)(void *),
+ void *vblank_cb_data)
{
struct mtk_disp_rdma *rdma = dev_get_drvdata(dev);

rdma->vblank_cb = vblank_cb;
rdma->vblank_cb_data = vblank_cb_data;
- rdma_update_bits(dev, DISP_REG_RDMA_INT_ENABLE, RDMA_FRAME_END_INT,
- RDMA_FRAME_END_INT);
}

-void mtk_rdma_disable_vblank(struct device *dev)
+void mtk_rdma_unregister_vblank_cb(struct device *dev)
{
struct mtk_disp_rdma *rdma = dev_get_drvdata(dev);

rdma->vblank_cb = NULL;
rdma->vblank_cb_data = NULL;
+}
+
+void mtk_rdma_enable_vblank(struct device *dev)
+{
+ rdma_update_bits(dev, DISP_REG_RDMA_INT_ENABLE, RDMA_FRAME_END_INT,
+ RDMA_FRAME_END_INT);
+}
+
+void mtk_rdma_disable_vblank(struct device *dev)
+{
rdma_update_bits(dev, DISP_REG_RDMA_INT_ENABLE, RDMA_FRAME_END_INT, 0);
}

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index d661edf7e0fe..e42a9bfa0ecb 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -152,6 +152,7 @@ static void mtk_drm_cmdq_pkt_destroy(struct cmdq_pkt *pkt)
static void mtk_drm_crtc_destroy(struct drm_crtc *crtc)
{
struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
+ int i;

mtk_mutex_put(mtk_crtc->mutex);
#if IS_REACHABLE(CONFIG_MTK_CMDQ)
@@ -162,6 +163,14 @@ static void mtk_drm_crtc_destroy(struct drm_crtc *crtc)
mtk_crtc->cmdq_client.chan = NULL;
}
#endif
+
+ for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
+ struct mtk_ddp_comp *comp;
+
+ comp = mtk_crtc->ddp_comp[i];
+ mtk_ddp_comp_unregister_vblank_cb(comp);
+ }
+
drm_crtc_cleanup(crtc);
}

@@ -616,7 +625,7 @@ static int mtk_drm_crtc_enable_vblank(struct drm_crtc *crtc)
struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[0];

- mtk_ddp_comp_enable_vblank(comp, mtk_crtc_ddp_irq, &mtk_crtc->base);
+ mtk_ddp_comp_enable_vblank(comp);

return 0;
}
@@ -916,6 +925,9 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
if (comp->funcs->ctm_set)
has_ctm = true;
}
+
+ mtk_ddp_comp_register_vblank_cb(comp, mtk_crtc_ddp_irq,
+ &mtk_crtc->base);
}

for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
index b4b682bc1991..028cf76b9531 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
@@ -297,6 +297,8 @@ static const struct mtk_ddp_comp_funcs ddp_ovl = {
.config = mtk_ovl_config,
.start = mtk_ovl_start,
.stop = mtk_ovl_stop,
+ .register_vblank_cb = mtk_ovl_register_vblank_cb,
+ .unregister_vblank_cb = mtk_ovl_unregister_vblank_cb,
.enable_vblank = mtk_ovl_enable_vblank,
.disable_vblank = mtk_ovl_disable_vblank,
.supported_rotations = mtk_ovl_supported_rotations,
@@ -321,6 +323,8 @@ static const struct mtk_ddp_comp_funcs ddp_rdma = {
.config = mtk_rdma_config,
.start = mtk_rdma_start,
.stop = mtk_rdma_stop,
+ .register_vblank_cb = mtk_rdma_register_vblank_cb,
+ .unregister_vblank_cb = mtk_rdma_unregister_vblank_cb,
.enable_vblank = mtk_rdma_enable_vblank,
.disable_vblank = mtk_rdma_disable_vblank,
.layer_nr = mtk_rdma_layer_nr,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
index 4c6a98662305..b83f24cb045f 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
@@ -48,9 +48,11 @@ struct mtk_ddp_comp_funcs {
unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
void (*start)(struct device *dev);
void (*stop)(struct device *dev);
- void (*enable_vblank)(struct device *dev,
- void (*vblank_cb)(void *),
- void *vblank_cb_data);
+ void (*register_vblank_cb)(struct device *dev,
+ void (*vblank_cb)(void *),
+ void *vblank_cb_data);
+ void (*unregister_vblank_cb)(struct device *dev);
+ void (*enable_vblank)(struct device *dev);
void (*disable_vblank)(struct device *dev);
unsigned int (*supported_rotations)(struct device *dev);
unsigned int (*layer_nr)(struct device *dev);
@@ -111,12 +113,25 @@ static inline void mtk_ddp_comp_stop(struct mtk_ddp_comp *comp)
comp->funcs->stop(comp->dev);
}

-static inline void mtk_ddp_comp_enable_vblank(struct mtk_ddp_comp *comp,
- void (*vblank_cb)(void *),
- void *vblank_cb_data)
+static inline void mtk_ddp_comp_register_vblank_cb(struct mtk_ddp_comp *comp,
+ void (*vblank_cb)(void *),
+ void *vblank_cb_data)
+{
+ if (comp->funcs && comp->funcs->register_vblank_cb)
+ comp->funcs->register_vblank_cb(comp->dev, vblank_cb,
+ vblank_cb_data);
+}
+
+static inline void mtk_ddp_comp_unregister_vblank_cb(struct mtk_ddp_comp *comp)
+{
+ if (comp->funcs && comp->funcs->unregister_vblank_cb)
+ comp->funcs->unregister_vblank_cb(comp->dev);
+}
+
+static inline void mtk_ddp_comp_enable_vblank(struct mtk_ddp_comp *comp)
{
if (comp->funcs && comp->funcs->enable_vblank)
- comp->funcs->enable_vblank(comp->dev, vblank_cb, vblank_cb_data);
+ comp->funcs->enable_vblank(comp->dev);
}

static inline void mtk_ddp_comp_disable_vblank(struct mtk_ddp_comp *comp)
--
2.35.1