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 91d60608a19ad0fac3ac705234469d48deca7292..ffc25e3db03129e263a3587d91de766a254faba8 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);