diff options
| author | Boris Brezillon <boris.brezillon@collabora.com> | 2024-12-17 10:24:57 +0100 |
|---|---|---|
| committer | Steven Price <steven.price@arm.com> | 2025-01-13 11:26:20 +0000 |
| commit | 57e233c3bd63f32d2c7e937db2e16b98f723ce2f (patch) | |
| tree | 35d75094c68e6525cc9e176c8c2f88220d7085af | |
| parent | 573b73e5ac2ce0d58859eace8218f3a7e9212186 (diff) | |
drm/panthor: Fix a race between the reset and suspend path
If a reset is scheduled when the suspend happens, we drop the
reset-pending info on the floor assuming the resume will fix things,
but the resume logic might try a fast reset. If we're lucky, the
fast reset fails and we fallback to a slow reset, but if the FW was
corrupted in a way that makes it partially functional (it boots but
doesn't quite do what it's expected to do), we won't notice immediately
that things are not working correctly, leading to a new reset further
down the road.
Fixes: 5fe909cae118 ("drm/panthor: Add the device logical block")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241217092457.1582053-1-boris.brezillon@collabora.com
| -rw-r--r-- | drivers/gpu/drm/panthor/panthor_device.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c index 0a37cfeeb181..a9da1d1eeb70 100644 --- a/drivers/gpu/drm/panthor/panthor_device.c +++ b/drivers/gpu/drm/panthor/panthor_device.c @@ -128,14 +128,11 @@ static void panthor_device_reset_work(struct work_struct *work) struct panthor_device *ptdev = container_of(work, struct panthor_device, reset.work); int ret = 0, cookie; - if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_ACTIVE) { - /* - * No need for a reset as the device has been (or will be) - * powered down - */ - atomic_set(&ptdev->reset.pending, 0); + /* If the device is entering suspend, we don't reset. A slow reset will + * be forced at resume time instead. + */ + if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_ACTIVE) return; - } if (!drm_dev_enter(&ptdev->base, &cookie)) return; @@ -477,6 +474,14 @@ int panthor_device_resume(struct device *dev) if (panthor_device_is_initialized(ptdev) && drm_dev_enter(&ptdev->base, &cookie)) { + /* If there was a reset pending at the time we suspended the + * device, we force a slow reset. + */ + if (atomic_read(&ptdev->reset.pending)) { + ptdev->reset.fast = false; + atomic_set(&ptdev->reset.pending, 0); + } + ret = panthor_device_resume_hw_components(ptdev); if (ret && ptdev->reset.fast) { drm_err(&ptdev->base, "Fast reset failed, trying a slow reset"); @@ -493,9 +498,6 @@ int panthor_device_resume(struct device *dev) goto err_suspend_devfreq; } - if (atomic_read(&ptdev->reset.pending)) - queue_work(ptdev->reset.wq, &ptdev->reset.work); - /* Clear all IOMEM mappings pointing to this device after we've * resumed. This way the fake mappings pointing to the dummy pages * are removed and the real iomem mapping will be restored on next |