On Mon, 21 Jun 2021 16:09:32 +0100 Steven Price steven.price@arm.com wrote:
On 21/06/2021 14:39, Boris Brezillon wrote:
If we don't do that, we have to wait for the job timeout to expire before the fault jobs gets killed.
Signed-off-by: Boris Brezillon boris.brezillon@collabora.com
Don't we need to do something here to allow recovery of the MMU context in the future? panfrost_mmu_disable() will zero out the MMU registers on the hardware, but AFAICS panfrost_mmu_enable() won't be called to restore the values until something evicts the address space (GPU power down/reset or just too many other processes).
The ideal would be to block submission of new jobs from this context and then wait until existing jobs have completed at which point the MMU state can be restored and jobs allowed again.
Uh, I assumed it'd be okay to have subsequent jobs coming from this context to fail with a BUS_FAULT until the context is closed. But what you suggest seems more robust.
But at a minimum I think we should have something like an 'MMU poisoned' bit that panfrost_mmu_as_get() can check.
Steve
drivers/gpu/drm/panfrost/panfrost_mmu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index 2a9bf30edc9d..d5c624e776f1 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -661,7 +661,7 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) if ((status & mask) == BIT(as) && (exception_type & 0xF8) == 0xC0) ret = panfrost_mmu_map_fault_addr(pfdev, as, addr);
if (ret)
if (ret) { /* terminal fault, print info about the fault */ dev_err(pfdev->dev, "Unhandled Page fault in AS%d at VA 0x%016llX\n"@@ -679,6 +679,10 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) access_type, access_type_name(pfdev, fault_status), source_id);
/* Disable the MMU to stop jobs on this AS immediately */panfrost_mmu_disable(pfdev, as);}status &= ~mask;
/* If we received new MMU interrupts, process them before returning. */