On Tue, Dec 02, 2025 at 02:35:38PM +0100, Boris Brezillon wrote:
> An AS can be disabled in the middle of a VM operation (VM being
> evicted from an AS slot, for instance). In that case, we need the
> locked section to be unlocked before releasing the slot.
>
> Fixes: 6e2d3b3e8589 ("drm/panthor: Add support for atomic page table updates")
> Signed-off-by: Boris Brezillon <[email protected]>
Reviewed-by: Liviu Dudau <[email protected]>
Best regards,
Liviu
> ---
> drivers/gpu/drm/panthor/panthor_mmu.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 3644af1a8e56..4ed28bd1b8ec 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -588,6 +588,7 @@ static int panthor_mmu_as_enable(struct panthor_device
> *ptdev, u32 as_nr,
> static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr,
> bool recycle_slot)
> {
> + struct panthor_vm *vm = ptdev->mmu->as.slots[as_nr].vm;
> int ret;
>
> /* Flush+invalidate RW caches, invalidate RO ones. */
> @@ -596,6 +597,16 @@ static int panthor_mmu_as_disable(struct panthor_device
> *ptdev, u32 as_nr,
> if (ret)
> return ret;
>
> + if (vm && vm->locked_region.size) {
> + /* Unlock the region if there a lock pending. */
> + ret = as_send_cmd_and_wait(ptdev, vm->as.id, AS_COMMAND_UNLOCK);
> + if (ret)
> + return ret;
> +
> + vm->locked_region.start = 0;
> + vm->locked_region.size = 0;
> + }
> +
> /* If the slot is going to be used immediately, don't bother changing
> * the config.
> */
> --
> 2.51.1
>
