[PATCH v2 3/3] drm/msm/adreno: Check for recognized GPU before bind

[Rob Clark]

If we have a newer dtb than kernel, we could end up in a situation where
the GPU device is present in the dtb, but not in the drivers device
table.  We don't want this to prevent the display from probing.  So
check that we recognize the GPU before adding the GPU component.

v2: use %pOF

Signed-off-by: Rob Clark <robin.clark at oss.qualcomm.com>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 29 ++++++++++++++++++----
 drivers/gpu/drm/msm/msm_drv.c              |  2 +-
 drivers/gpu/drm/msm/msm_gpu.h              |  1 +
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 778e6ae7f137..0d12454b1f2e 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -178,6 +178,26 @@ static int find_chipid(struct device_node *node, uint32_t *chipid)
 	return 0;
 }
 
+bool adreno_has_gpu(struct device_node *node)
+{
+	const struct adreno_info *info;
+	uint32_t chip_id;
+	int ret;
+
+	ret = find_chipid(node, &chip_id);
+	if (ret)
+		return false;
+
+	info = adreno_info(chip_id);
+	if (!info) {
+		pr_warn("%pOF: Unknown GPU revision: %"ADRENO_CHIPID_FMT"\n",
+			node, ADRENO_CHIPID_ARGS(chip_id));
+		return false;
+	}
+
+	return true;
+}
+
 static int adreno_bind(struct device *dev, struct device *master, void *data)
 {
 	static struct adreno_platform_config config = {};
@@ -188,18 +208,17 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
 	int ret;
 
 	ret = find_chipid(dev->of_node, &config.chip_id);
-	if (ret)
+	/* We shouldn't have gotten this far if we can't parse the chip_id */
+	if (WARN_ON(ret))
 		return ret;
 
 	dev->platform_data = &config;
 	priv->gpu_pdev = to_platform_device(dev);
 
 	info = adreno_info(config.chip_id);
-	if (!info) {
-		dev_warn(drm->dev, "Unknown GPU revision: %"ADRENO_CHIPID_FMT"\n",
-			ADRENO_CHIPID_ARGS(config.chip_id));
+	/* We shouldn't have gotten this far if we don't recognize the GPU: */
+	if (!WARN_ON(info))
 		return -ENXIO;
-	}
 
 	config.info = info;
 
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 87ee9839ca4a..40eb04bab35e 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -956,7 +956,7 @@ static int add_gpu_components(struct device *dev,
 	if (!np)
 		return 0;
 
-	if (of_device_is_available(np))
+	if (of_device_is_available(np) && adreno_has_gpu(np))
 		drm_of_component_match_add(dev, matchptr, component_compare_of, np);
 
 	of_node_put(np);
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 5508885d865f..56bd1a646b83 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -729,6 +729,7 @@ msm_gpu_create_private_vm(struct msm_gpu *gpu, struct task_struct *task,
 void msm_gpu_cleanup(struct msm_gpu *gpu);
 
 struct msm_gpu *adreno_load_gpu(struct drm_device *dev);
+bool adreno_has_gpu(struct device_node *node);
 void __init adreno_register(void);
 void __exit adreno_unregister(void);
 
-- 
2.49.0