On 12/15/2017 09:03 PM, Jordan Crouse wrote:
On Thu, Dec 14, 2017 at 11:11:50AM +0530, Archit Taneja wrote:The msm/kms driver should work even if there is no GPU device specified in DT. Currently, we get a NULL dereference crash in adreno_load_gpu since the driver assumes that priv->gpu_pdev is non-NULL. Perform an additional check on priv->gpu_pdev before trying to retrieve the msm_gpu pointer from it. Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time) Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx> --- drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c index 05022ea2a007..ac60cf3c794e 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_device.c +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c @@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev) struct msm_gpu *adreno_load_gpu(struct drm_device *dev) { struct msm_drm_private *priv = dev->dev_private; - struct platform_device *pdev = priv->gpu_pdev; - struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev); + struct platform_device *pdev; + struct msm_gpu *gpu; int ret;+ pdev = priv->gpu_pdev;+ if (!pdev) { + dev_dbg(dev->dev, "no adreno platform device found\n"); + return NULL; + } + + gpu = platform_get_drvdata(pdev); if (!gpu) { dev_err(dev->dev, "no adreno device\n"); return NULL;Obviously correct fix but I can't help but think that we should share the same error message, so something like: struct msm_gpu *gpu = NULL; .. if (priv->gpu_pdev) gpu = platform_get_drvdata(priv->gpu_pdev); if (!gpu) { dev_err(dev->dev, "No GPU device was was found\n"); return NULL; } (also, I can't help but think maybe that dev_err should be a ONCE so you don't get a nasty message every time you open the file descriptor).
This approach looks better. I'll re-spin. Thanks, Archit
Jordan
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