drm/msm: fix NULL-deref on irq uninstall

commit cd459c005de3e2b855a8cc7768e633ce9d018e9f upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index a4a2825652d2afd2adcafac1cda9693992d87fdb..750b597e659ef9dc80ef1530540ececfdd562e97 100644 (file)
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -250,9 +250,11 @@ 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);