drm/msm/adreno: fix runtime PM imbalance at gpu load

BugLink: https://bugs.launchpad.net/bugs/2028580
commit 0d997f95b70f98987ae031a89677c13e0e223670 upstream.

A recent commit moved enabling of runtime PM to GPU load time (first
open()) but failed to update the error paths so that runtime PM is
disabled if initialisation of the GPU fails. This would trigger a
warning about the unbalanced disable count on the next open() attempt.

Note that pm_runtime_put_noidle() is sufficient to balance the usage
count when pm_runtime_put_sync() fails (and is chosen over
pm_runtime_resume_and_get() for consistency reasons).

Fixes: 4b18299b3365 ("drm/msm/adreno: Defer enabling runpm until hw_init()")
Cc: stable@vger.kernel.org      # 6.0
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Patchwork: https://patchwork.freedesktop.org/patch/524971/
Link: https://lore.kernel.org/r/20230303164807.13124-3-johan+linaro@kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index cd009d56d35d5b67d127989c7cc6d108a31fc859..d9100e3870bc458f7dae218045d41fac1b151a84 100644 (file)
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -440,20 +440,21 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 
        ret = pm_runtime_get_sync(&pdev->dev);
        if (ret < 0) {
-               pm_runtime_put_sync(&pdev->dev);
+               pm_runtime_put_noidle(&pdev->dev);
                DRM_DEV_ERROR(dev->dev, "Couldn't power up the GPU: %d\n", ret);
-               return NULL;
+               goto err_disable_rpm;
        }
 
        mutex_lock(&gpu->lock);
        ret = msm_gpu_hw_init(gpu);
        mutex_unlock(&gpu->lock);
-       pm_runtime_put_autosuspend(&pdev->dev);
        if (ret) {
                DRM_DEV_ERROR(dev->dev, "gpu hw init failed: %d\n", ret);
-               return NULL;
+               goto err_put_rpm;
        }
 
+       pm_runtime_put_autosuspend(&pdev->dev);
+
 #ifdef CONFIG_DEBUG_FS
        if (gpu->funcs->debugfs_init) {
                gpu->funcs->debugfs_init(gpu, dev->primary);
@@ -462,6 +463,13 @@ struct msm_gpu *adreno_load_gpu(struct drm_device *dev)
 #endif
 
        return gpu;
+
+err_put_rpm:
+       pm_runtime_put_sync(&pdev->dev);
+err_disable_rpm:
+       pm_runtime_disable(&pdev->dev);
+
+       return NULL;
 }
 
 static int find_chipid(struct device *dev, struct adreno_rev *rev)