drm/msm: Fix potential Oops in a6xx_gmu_rpmh_init()

There are two problems here:
1) The "seqptr" is used uninitalized when we free it at the end.
2) The a6xx_gmu_get_mmio() function returns error pointers.  It never
   returns true.

Fixes: 64245fc55172 ("drm/msm/a6xx: use AOP-initialized PDC for a650")
Fixes: f8fc924e088e ("drm/msm/a6xx: Fix PDC register overlap")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20211004134530.GB11689@kili
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 049f7b4..71e52b2 100644 (file)
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -516,11 +516,11 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
        struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
        struct platform_device *pdev = to_platform_device(gmu->dev);
        void __iomem *pdcptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc");
-       void __iomem *seqptr;
+       void __iomem *seqptr = NULL;
        uint32_t pdc_address_offset;
        bool pdc_in_aop = false;
 
-       if (!pdcptr)
+       if (IS_ERR(pdcptr))
                goto err;
 
        if (adreno_is_a650(adreno_gpu) || adreno_is_a660_family(adreno_gpu))
@@ -532,7 +532,7 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
 
        if (!pdc_in_aop) {
                seqptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc_seq");
-               if (!seqptr)
+               if (IS_ERR(seqptr))
                        goto err;
        }