drm/msm: Fix removal of valid error case when checking speed_bin

Commit 7bf168c8fe8c  ("drm/msm: Fix speed-bin support not to
access outside valid memory"), reworked the nvmem reading of
"speed_bin", but in doing so dropped handling of the -ENOENT
case which was previously documented as "fine".

That change resulted in the db845c board display to fail to
start, with the following error:

adreno 5000000.gpu: [drm:a6xx_gpu_init] *ERROR* failed to read speed-bin (-2). Some OPPs may not be supported by hardware

Thus, this patch simply re-adds the ENOENT handling so the lack
of the speed_bin entry isn't fatal for display, and gets things
working on db845c.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: YongQin Liu <yongqin.liu@linaro.org>
Reported-by: YongQin Liu <yongqin.liu@linaro.org>
Fixes: 7bf168c8fe8c  ("drm/msm: Fix speed-bin support not to access outside valid memory")
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Akhil P Oommen <akhilpo@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Message-Id: <20210330013408.2532048-1-john.stultz@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 690409ca8a18681dc78a71c9a9448480457b024a..cb2df8736ca85d7fc9a729095747dab3af75f8ee 100644 (file)
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1406,7 +1406,13 @@ static int a6xx_set_supported_hw(struct device *dev, struct a6xx_gpu *a6xx_gpu,
        int ret;
 
        ret = nvmem_cell_read_u16(dev, "speed_bin", &speedbin);
-       if (ret) {
+       /*
+        * -ENOENT means that the platform doesn't support speedbin which is
+        * fine
+        */
+       if (ret == -ENOENT) {
+               return 0;
+       } else if (ret) {
                DRM_DEV_ERROR(dev,
                              "failed to read speed-bin (%d). Some OPPs may not be supported by hardware",
                              ret);