drm/msm: fix NULL-deref on irq uninstall

In case of early initialisation errors and on platforms that do not use
the DPU controller, the deinitilisation code can be called with the kms
pointer set to NULL.

Fixes: f026e431cf86 ("drm/msm: Convert to Linux IRQ interfaces")
Cc: stable@vger.kernel.org	# 5.14
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/525104/
Link: https://lore.kernel.org/r/20230306100722.28485-5-johan+linaro@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 91d6060..ffc25e3 100644 (file)
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -252,9 +252,11 @@ static int msm_drm_uninit(struct device *dev)
                drm_bridge_remove(priv->bridges[i]);
        priv->num_bridges = 0;
 
-       pm_runtime_get_sync(dev);
-       msm_irq_uninstall(ddev);
-       pm_runtime_put_sync(dev);
+       if (kms) {
+               pm_runtime_get_sync(dev);
+               msm_irq_uninstall(ddev);
+               pm_runtime_put_sync(dev);
+       }
 
        if (kms && kms->funcs)
                kms->funcs->destroy(kms);