6.14-stable review patch. If anyone has any objections, please let me know.
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From: Boris Brezillon boris.brezillon@collabora.com
[ Upstream commit 57e233c3bd63f32d2c7e937db2e16b98f723ce2f ]
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... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/panthor/panthor_device.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c index 0a37cfeeb181c..a9da1d1eeb707 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