| Message ID | 20210201082116.267208-2-boris.brezillon@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panfrost: MMU fixes | expand |
On 01/02/2021 08:21, Boris Brezillon wrote: > When a fault is handled it will unblock the GPU which will continue > executing its shader and might fault almost immediately on a different > page. If we clear interrupts after handling the fault we might miss new > faults, so clear them before. > > Cc: <stable@vger.kernel.org> > Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations") > Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Good catch (although this oddly rings a bell - so perhaps it was me you discussed it with before) Reviewed-by: Steven Price <steven.price@arm.com> > --- > drivers/gpu/drm/panfrost/panfrost_mmu.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c > index 7c1b3481b785..904d63450862 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c > +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c > @@ -593,6 +593,8 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) > access_type = (fault_status >> 8) & 0x3; > source_id = (fault_status >> 16); > > + mmu_write(pfdev, MMU_INT_CLEAR, mask); > + > /* Page fault only */ > ret = -1; > if ((status & mask) == BIT(i) && (exception_type & 0xF8) == 0xC0) > @@ -616,8 +618,6 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) > access_type, access_type_name(pfdev, fault_status), > source_id); > > - mmu_write(pfdev, MMU_INT_CLEAR, mask); > - > status &= ~mask; > } > >
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index 7c1b3481b785..904d63450862 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -593,6 +593,8 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) access_type = (fault_status >> 8) & 0x3; source_id = (fault_status >> 16); + mmu_write(pfdev, MMU_INT_CLEAR, mask); + /* Page fault only */ ret = -1; if ((status & mask) == BIT(i) && (exception_type & 0xF8) == 0xC0) @@ -616,8 +618,6 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data) access_type, access_type_name(pfdev, fault_status), source_id); - mmu_write(pfdev, MMU_INT_CLEAR, mask); - status &= ~mask; }
When a fault is handled it will unblock the GPU which will continue executing its shader and might fault almost immediately on a different page. If we clear interrupts after handling the fault we might miss new faults, so clear them before. Cc: <stable@vger.kernel.org> Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations") Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)