Use TRANSTAB == 0 as a way to detect if an AS slot is idle. This allows us to make panthor_mmu_as_disable() a NOP when it's called after a SOFT_RESET, which will be needed for our unplug rework.
Signed-off-by: Boris Brezillon <[email protected]> --- drivers/gpu/drm/panthor/panthor_mmu.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index 1b401fd0d2d7..a48466788f4d 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -634,6 +634,10 @@ static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 slot, lockdep_assert_held(&ptdev->mmu->as.slots_lock); + /* The AS was disabled already, nothing to do. */ + if (!gpu_read64(mmu->iomem, AS_TRANSTAB(slot))) + return 0; + panthor_mmu_irq_disable_events(&ptdev->mmu->irq, panthor_mmu_as_fault_mask(ptdev, slot)); @@ -656,11 +660,17 @@ static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 slot, if (recycle_slot) return 0; - gpu_write64(mmu->iomem, AS_TRANSTAB(slot), 0); - gpu_write64(mmu->iomem, AS_MEMATTR(slot), 0); gpu_write64(mmu->iomem, AS_TRANSCFG(slot), AS_TRANSCFG_ADRMODE_UNMAPPED); + ret = as_send_cmd_and_wait(ptdev, slot, AS_COMMAND_UPDATE); + if (ret) + return ret; - return as_send_cmd_and_wait(ptdev, slot, AS_COMMAND_UPDATE); + /* We reset the other fields late to ensure that, if something fails, + * the page table is considered active (TRANSTAB != NULL). + */ + gpu_write64(mmu->iomem, AS_MEMATTR(slot), 0); + gpu_write64(mmu->iomem, AS_TRANSTAB(slot), 0); + return 0; } static u32 panthor_mmu_fault_mask(struct panthor_device *ptdev, u32 value) -- 2.55.0
