diff options
| author | Ketil Johnsen <ketil.johnsen@arm.com> | 2025-10-22 12:32:41 +0200 |
|---|---|---|
| committer | Liviu Dudau <liviu.dudau@arm.com> | 2025-11-03 14:25:22 +0000 |
| commit | 08be57e6e8aa20ea5a6dd2552e38ac168d6a9b11 (patch) | |
| tree | 2dd789c2c6d9c1745c5004d3a85951878bebd7a9 /drivers/gpu/drm/panthor | |
| parent | 65c22519cf687ca3a4275241b3d8b7f105648523 (diff) | |
drm/panthor: Fix race with suspend during unplug
There is a race between panthor_device_unplug() and
panthor_device_suspend() which can lead to IRQ handlers running on a
powered down GPU. This is how it can happen:
- unplug routine calls drm_dev_unplug()
- panthor_device_suspend() can now execute, and will skip a lot of
important work because the device is currently marked as unplugged.
- IRQs will remain active in this case and IRQ handlers can therefore
try to access a powered down GPU.
The fix is simply to take the PM ref in panthor_device_unplug() a
little bit earlier, before drm_dev_unplug().
Signed-off-by: Ketil Johnsen <ketil.johnsen@arm.com>
Fixes: 5fe909cae118a ("drm/panthor: Add the device logical block")
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patch.msgid.link/20251022103242.1083311-1-ketil.johnsen@arm.com
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Diffstat (limited to 'drivers/gpu/drm/panthor')
| -rw-r--r-- | drivers/gpu/drm/panthor/panthor_device.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c index f3ae93153b6e..83adacaa5760 100644 --- a/drivers/gpu/drm/panthor/panthor_device.c +++ b/drivers/gpu/drm/panthor/panthor_device.c @@ -84,6 +84,8 @@ void panthor_device_unplug(struct panthor_device *ptdev) return; } + drm_WARN_ON(&ptdev->base, pm_runtime_get_sync(ptdev->base.dev) < 0); + /* Call drm_dev_unplug() so any access to HW blocks happening after * that point get rejected. */ @@ -94,8 +96,6 @@ void panthor_device_unplug(struct panthor_device *ptdev) */ mutex_unlock(&ptdev->unplug.lock); - drm_WARN_ON(&ptdev->base, pm_runtime_get_sync(ptdev->base.dev) < 0); - /* Now, try to cleanly shutdown the GPU before the device resources * get reclaimed. */ |