2021-03-17 02:58:02

by Bjorn Andersson

[permalink] [raw]
Subject: [PATCH] drm/msm: Remove need for reiterating the compatibles

After spending a non-negligible time trying to figure out why
dpu_kms_init() would dereference a NULL dpu_kms->pdev, it turns out that
in addition to adding the new compatible to the msm_drv of_match_table
one also need to teach add_display_components() to register the child
nodes - which includes the DPU platform_device.

Replace the open coded test for compatibles with a check against the
match data of the mdss device to save others this trouble in the future.

Signed-off-by: Bjorn Andersson <[email protected]>
---
drivers/gpu/drm/msm/msm_drv.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 94525ac76d4e..0f6e186a609d 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -1173,10 +1173,11 @@ static int compare_name_mdp(struct device *dev, void *data)
return (strstr(dev_name(dev), "mdp") != NULL);
}

-static int add_display_components(struct device *dev,
+static int add_display_components(struct platform_device *pdev,
struct component_match **matchptr)
{
struct device *mdp_dev;
+ struct device *dev = &pdev->dev;
int ret;

/*
@@ -1185,9 +1186,9 @@ static int add_display_components(struct device *dev,
* Populate the children devices, find the MDP5/DPU node, and then add
* the interfaces to our components list.
*/
- if (of_device_is_compatible(dev->of_node, "qcom,mdss") ||
- of_device_is_compatible(dev->of_node, "qcom,sdm845-mdss") ||
- of_device_is_compatible(dev->of_node, "qcom,sc7180-mdss")) {
+ switch (get_mdp_ver(pdev)) {
+ case KMS_MDP5:
+ case KMS_DPU:
ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
if (ret) {
DRM_DEV_ERROR(dev, "failed to populate children devices\n");
@@ -1206,9 +1207,11 @@ static int add_display_components(struct device *dev,
/* add the MDP component itself */
drm_of_component_match_add(dev, matchptr, compare_of,
mdp_dev->of_node);
- } else {
+ break;
+ case KMS_MDP4:
/* MDP4 */
mdp_dev = dev;
+ break;
}

ret = add_components_mdp(mdp_dev, matchptr);
@@ -1273,7 +1276,7 @@ static int msm_pdev_probe(struct platform_device *pdev)
int ret;

if (get_mdp_ver(pdev)) {
- ret = add_display_components(&pdev->dev, &match);
+ ret = add_display_components(pdev, &match);
if (ret)
return ret;
}
--
2.29.2