On 03/06/2022 12:42, Vinod Polimera wrote:
During probe defer, drm device is not initialized and an external trigger to shutdown is trying to clean up drm device leading to crash. Add checks to avoid drm device cleanup in such cases.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8
Call trace:
drm_atomic_helper_shutdown+0x44/0x144 msm_pdev_shutdown+0x2c/0x38 platform_shutdown+0x2c/0x38 device_shutdown+0x158/0x210 kernel_restart_prepare+0x40/0x4c kernel_restart+0x20/0x6c __arm64_sys_reboot+0x194/0x23c invoke_syscall+0x50/0x13c el0_svc_common+0xa0/0x17c do_el0_svc_compat+0x28/0x34 el0_svc_compat+0x20/0x70 el0t_32_sync_handler+0xa8/0xcc el0t_32_sync+0x1a8/0x1ac
Changes in v2:
- Add fixes tag.
Fixes: 623f279c778 ("drm/msm: fix shutdown hook in case GPU components failed to bind") Signed-off-by: Vinod Polimera quic_vpolimer@quicinc.com
drivers/gpu/drm/msm/msm_drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 4448536..d62ac66 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -142,6 +142,9 @@ static void msm_irq_uninstall(struct drm_device *dev) struct msm_drm_private *priv = dev->dev_private; struct msm_kms *kms = priv->kms;
- if (!irq_has_action(kms->irq))
return;
As a second thought I'd still prefer a variable here. irq_has_action would check that there is _any_ IRQ handler for this IRQ. While we do not have anybody sharing this IRQ, I'd prefer to be clear here, that we do not want to uninstall our IRQ handler rather than any IRQ handler.
- kms->funcs->irq_uninstall(kms); if (kms->irq_requested) free_irq(kms->irq, dev);
@@ -259,6 +262,7 @@ static int msm_drm_uninit(struct device *dev)
ddev->dev_private = NULL; drm_dev_put(ddev);
priv->dev = NULL;
destroy_workqueue(priv->wq);
@@ -1167,7 +1171,7 @@ void msm_drv_shutdown(struct platform_device *pdev) struct msm_drm_private *priv = platform_get_drvdata(pdev); struct drm_device *drm = priv ? priv->dev : NULL;
- if (!priv || !priv->kms)
if (!priv || !priv->kms || !drm) return;
drm_atomic_helper_shutdown(drm);