[PATCH RESEND v5] drm/mediatek: dpi/dsi: fix possible_crtcs calculation

From: Michael Walle
Date: Thu Jun 06 2024 - 05:22:38 EST


mtk_find_possible_crtcs() assumes that the main path will always have
the CRTC with id 0, the ext id 1 and the third id 2. This is only true
if the paths are all available. But paths are optional (see also
comment in mtk_drm_kms_init()), e.g. the main path might not be enabled
or available at all. Then the CRTC IDs will shift one up, e.g. ext will
be 0 and the third path will be 1.

To fix that, dynamically calculate the IDs by the presence of the paths.

While at it, make the return code a signed one and return -ENODEV if no
path is found and handle the error in the callers.

Fixes: 5aa8e7647676 ("drm/mediatek: dpi/dsi: Change the getting possible_crtc way")
Suggested-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Signed-off-by: Michael Walle <mwalle@xxxxxxxxxx>
---
You can find v4 at [1]. Unfortunately, it was never applied and in the
meantime there was a change in mtk_find_possible_crtcs(). So I've
dropped Nícolas Reviewed and Tested-by tags and Angelos Reviewed-by
tag.

[1] https://lore.kernel.org/r/20230905084922.3908121-2-mwalle@xxxxxxxxxx/
---
drivers/gpu/drm/mediatek/mtk_ddp_comp.c | 105 ++++++++++++++++--------
drivers/gpu/drm/mediatek/mtk_ddp_comp.h | 2 +-
drivers/gpu/drm/mediatek/mtk_dpi.c | 5 +-
drivers/gpu/drm/mediatek/mtk_dsi.c | 5 +-
4 files changed, 78 insertions(+), 39 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
index 17b036411292..9a8c1cace8a0 100644
--- a/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
+++ b/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
@@ -514,29 +514,42 @@ static bool mtk_ddp_comp_find(struct device *dev,
return false;
}

-static unsigned int mtk_ddp_comp_find_in_route(struct device *dev,
- const struct mtk_drm_route *routes,
- unsigned int num_routes,
- struct mtk_ddp_comp *ddp_comp)
+static int mtk_ddp_comp_find_in_route(struct device *dev,
+ const struct mtk_drm_route *routes,
+ unsigned int num_routes,
+ struct mtk_ddp_comp *ddp_comp)
{
- int ret;
unsigned int i;

- if (!routes) {
- ret = -EINVAL;
- goto err;
- }
+ if (!routes)
+ return -EINVAL;

for (i = 0; i < num_routes; i++)
if (dev == ddp_comp[routes[i].route_ddp].dev)
return BIT(routes[i].crtc_id);

- ret = -ENODEV;
-err:
+ return -ENODEV;
+}

- DRM_INFO("Failed to find comp in ddp table, ret = %d\n", ret);
+static bool mtk_ddp_path_available(const unsigned int *path,
+ unsigned int path_len,
+ struct device_node **comp_node)
+{
+ unsigned int i;

- return 0;
+ if (!path || !path_len)
+ return false;
+
+ for (i = 0U; i < path_len; i++) {
+ /* OVL_ADAPTOR doesn't have a device node */
+ if (path[i] == DDP_COMPONENT_DRM_OVL_ADAPTOR)
+ continue;
+
+ if (!comp_node[path[i]])
+ return false;
+ }
+
+ return true;
}

int mtk_ddp_comp_get_id(struct device_node *node,
@@ -554,32 +567,52 @@ int mtk_ddp_comp_get_id(struct device_node *node,
return -EINVAL;
}

-unsigned int mtk_find_possible_crtcs(struct drm_device *drm, struct device *dev)
+int mtk_find_possible_crtcs(struct drm_device *drm, struct device *dev)
{
struct mtk_drm_private *private = drm->dev_private;
- unsigned int ret = 0;
-
- if (mtk_ddp_comp_find(dev,
- private->data->main_path,
- private->data->main_len,
- private->ddp_comp))
- ret = BIT(0);
- else if (mtk_ddp_comp_find(dev,
- private->data->ext_path,
- private->data->ext_len,
- private->ddp_comp))
- ret = BIT(1);
- else if (mtk_ddp_comp_find(dev,
- private->data->third_path,
- private->data->third_len,
- private->ddp_comp))
- ret = BIT(2);
- else
- ret = mtk_ddp_comp_find_in_route(dev,
- private->data->conn_routes,
- private->data->num_conn_routes,
- private->ddp_comp);
+ const struct mtk_mmsys_driver_data *data;
+ struct mtk_drm_private *priv_n;
+ int i = 0, j;
+ int ret;

+ for (j = 0; j < private->data->mmsys_dev_num; j++) {
+ priv_n = private->all_drm_private[j];
+ data = priv_n->data;
+
+ if (mtk_ddp_path_available(data->main_path, data->main_len,
+ priv_n->comp_node)) {
+ if (mtk_ddp_comp_find(dev, data->main_path,
+ data->main_len,
+ priv_n->ddp_comp))
+ return BIT(i);
+ i++;
+ }
+
+ if (mtk_ddp_path_available(data->ext_path, data->ext_len,
+ priv_n->comp_node)) {
+ if (mtk_ddp_comp_find(dev, data->ext_path,
+ data->ext_len,
+ priv_n->ddp_comp))
+ return BIT(i);
+ i++;
+ }
+
+ if (mtk_ddp_path_available(data->third_path, data->third_len,
+ priv_n->comp_node)) {
+ if (mtk_ddp_comp_find(dev, data->third_path,
+ data->third_len,
+ priv_n->ddp_comp))
+ return BIT(i);
+ i++;
+ }
+ }
+
+ ret = mtk_ddp_comp_find_in_route(dev,
+ private->data->conn_routes,
+ private->data->num_conn_routes,
+ private->ddp_comp);
+
+ DRM_INFO("Failed to find comp in ddp table, ret = %d\n", ret);
return ret;
}

diff --git a/drivers/gpu/drm/mediatek/mtk_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_ddp_comp.h
index 26236691ce4c..e2ea19d5ddcb 100644
--- a/drivers/gpu/drm/mediatek/mtk_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_ddp_comp.h
@@ -326,7 +326,7 @@ static inline void mtk_ddp_comp_encoder_index_set(struct mtk_ddp_comp *comp)

int mtk_ddp_comp_get_id(struct device_node *node,
enum mtk_ddp_comp_type comp_type);
-unsigned int mtk_find_possible_crtcs(struct drm_device *drm, struct device *dev);
+int mtk_find_possible_crtcs(struct drm_device *drm, struct device *dev);
int mtk_ddp_comp_init(struct device_node *comp_node, struct mtk_ddp_comp *comp,
unsigned int comp_id);
enum mtk_ddp_comp_type mtk_ddp_comp_get_type(unsigned int comp_id);
diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 5c86aa0b75b2..b894be9f1f53 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -814,7 +814,10 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
return ret;
}

- dpi->encoder.possible_crtcs = mtk_find_possible_crtcs(drm_dev, dpi->dev);
+ ret = mtk_find_possible_crtcs(drm_dev, dpi->dev);
+ if (ret < 0)
+ goto err_cleanup;
+ dpi->encoder.possible_crtcs = ret;

ret = drm_bridge_attach(&dpi->encoder, &dpi->bridge, NULL,
DRM_BRIDGE_ATTACH_NO_CONNECTOR);
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 2b0ac859a653..b450b7223aa2 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -861,7 +861,10 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
return ret;
}

- dsi->encoder.possible_crtcs = mtk_find_possible_crtcs(drm, dsi->host.dev);
+ ret = mtk_find_possible_crtcs(drm, dsi->host.dev);
+ if (ret < 0)
+ goto err_cleanup_encoder;
+ dsi->encoder.possible_crtcs = ret;

ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
DRM_BRIDGE_ATTACH_NO_CONNECTOR);
--
2.39.2