[PATCH] drm/msm/adreno: fix gpu probe if no interconnect-names

[Rob Clark]

From: Rob Clark <robdclark at chromium.org>

If there is no interconnect-names, but there is an interconnects
property, then of_icc_get(dev, "gfx-mem"); would return an error
rather than NULL.

Also, if there is no interconnect-names property, there will never
be a ocmem path.  But of_icc_get(dev, "ocmem") would return -EINVAL
instead of -ENODATA.  Just don't bother trying in this case.

Fixes: 8e29fb37b301 ("drm/msm: handle for EPROBE_DEFER for of_icc_get")
Signed-off-by: Rob Clark <robdclark at chromium.org>
---
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 0527e85184e1..c4ac998b90c8 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -979,6 +979,7 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 	struct adreno_platform_config *config = dev->platform_data;
 	struct msm_gpu_config adreno_gpu_config  = { 0 };
 	struct msm_gpu *gpu = &adreno_gpu->base;
+	bool has_interconnect_names = true;
 	int ret;
 
 	adreno_gpu->funcs = funcs;
@@ -1005,12 +1006,13 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 
 	/* Check for an interconnect path for the bus */
 	gpu->icc_path = of_icc_get(dev, "gfx-mem");
-	if (!gpu->icc_path) {
+	if (IS_ERR_OR_NULL(gpu->icc_path)) {
 		/*
 		 * Keep compatbility with device trees that don't have an
 		 * interconnect-names property.
 		 */
 		gpu->icc_path = of_icc_get(dev, NULL);
+		has_interconnect_names = false;
 	}
 	if (IS_ERR(gpu->icc_path)) {
 		ret = PTR_ERR(gpu->icc_path);
@@ -1018,7 +1020,9 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 		return ret;
 	}
 
-	gpu->ocmem_icc_path = of_icc_get(dev, "ocmem");
+	if (has_interconnect_names)
+		gpu->ocmem_icc_path = of_icc_get(dev, "ocmem");
+
 	if (IS_ERR(gpu->ocmem_icc_path)) {
 		ret = PTR_ERR(gpu->ocmem_icc_path);
 		gpu->ocmem_icc_path = NULL;
-- 
2.26.2