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drm/imagination: Fix kernel crash when hard resetting the GPU

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The GPU hard reset sequence calls pm_runtime_force_suspend() and
pm_runtime_force_resume(), which according to their documentation should
only be used during system-wide PM transitions to sleep states.

The main issue though is that depending on some internal runtime PM
state as seen by pm_runtime_force_suspend() (whether the usage count is
<= 1), pm_runtime_force_resume() might not resume the device unless
needed. If that happens, the runtime PM resume callback
pvr_power_device_resume() is not called, the GPU clocks are not
re-enabled, and the kernel crashes on the next attempt to access GPU
registers as part of the power-on sequence.

Replace calls to pm_runtime_force_suspend() and
pm_runtime_force_resume() with direct calls to the driver's runtime PM
callbacks, pvr_power_device_suspend() and pvr_power_device_resume(),
to ensure clocks are re-enabled and avoid the kernel crash.

Fixes: cc1aeedb98 ("drm/imagination: Implement firmware infrastructure and META FW support")
Signed-off-by: Alessio Belle <alessio.belle@imgtec.com>
Reviewed-by: Matt Coster <matt.coster@imgtec.com>
Link: https://lore.kernel.org/r/20250624-fix-kernel-crash-gpu-hard-reset-v1-1-6d24810d72a6@imgtec.com
Cc: stable@vger.kernel.org
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
This commit is contained in:
Alessio Belle
2025-06-24 15:22:08 +01:00
committed by Matt Coster
parent 44306a684c
commit d38376b3ee
1 changed files with 2 additions and 2 deletions
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4
drivers/gpu/drm/imagination/pvr_power.c
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@@ -386,13 +386,13 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
if (!err) {
if (hard_reset) {
pvr_dev->fw_dev.booted = false;
WARN_ON(pm_runtime_force_suspend(from_pvr_device(pvr_dev)->dev));
WARN_ON(pvr_power_device_suspend(from_pvr_device(pvr_dev)->dev));
err = pvr_fw_hard_reset(pvr_dev);
if (err)
goto err_device_lost;
err = pm_runtime_force_resume(from_pvr_device(pvr_dev)->dev);
err = pvr_power_device_resume(from_pvr_device(pvr_dev)->dev);
pvr_dev->fw_dev.booted = true;
if (err)
goto err_device_lost;