On 21/06/2021 14:39, Boris Brezillon wrote:
> If we can recover from a fault without a reset there's no reason to
> issue one.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/panfrost/panfrost_device.c | 9 ++++++
> drivers/gpu/drm/panfrost/panfrost_device.h | 2 ++
> drivers/gpu/drm/panfrost/panfrost_job.c | 35 ++++++++++++++--------
> 3 files changed, 34 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> index 2de011cee258..ac76e8646e97 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -383,6 +383,15 @@ int panfrost_exception_to_error(u32 exception_code)
> return panfrost_exception_infos[exception_code].error;
> }
>
> +bool panfrost_exception_needs_reset(const struct panfrost_device *pfdev,
> + u32 exception_code)
> +{
> + /* Right now, none of the GPU we support need a reset, but this
> + * might change (e.g. Valhall GPUs require a when a BUS_FAULT occurs).
NITs: ^ some ^ reset
Or just drop the example for now.
> + */
> + return false;
> +}
> +
> void panfrost_device_reset(struct panfrost_device *pfdev)
> {
> panfrost_gpu_soft_reset(pfdev);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 498c7b5dccd0..95e6044008d2 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -175,6 +175,8 @@ int panfrost_device_suspend(struct device *dev);
>
> const char *panfrost_exception_name(u32 exception_code);
> int panfrost_exception_to_error(u32 exception_code);
> +bool panfrost_exception_needs_reset(const struct panfrost_device *pfdev,
> + u32 exception_code);
>
> static inline void
> panfrost_device_schedule_reset(struct panfrost_device *pfdev)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index be5d3e4a1d0a..aedc604d331c 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -493,27 +493,38 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
>
> if (status & JOB_INT_MASK_ERR(j)) {
> enum panfrost_queue_status old_status;
> + u32 js_status = job_read(pfdev, JS_STATUS(j));
>
> job_write(pfdev, JS_COMMAND_NEXT(j), JS_COMMAND_NOP);
>
> dev_err(pfdev->dev, "js fault, js=%d, status=%s, head=0x%x, tail=0x%x",
> j,
> - panfrost_exception_name(job_read(pfdev, JS_STATUS(j))),
> + panfrost_exception_name(js_status),
> job_read(pfdev, JS_HEAD_LO(j)),
> job_read(pfdev, JS_TAIL_LO(j)));
>
> - /*
> - * When the queue is being restarted we don't report
> - * faults directly to avoid races between the timeout
> - * and reset handlers. panfrost_scheduler_start() will
> - * call drm_sched_fault() after the queue has been
> - * started if status == FAULT_PENDING.
> + /* If we need a reset, signal it to the reset handler,
> + * otherwise, update the fence error field and signal
> + * the job fence.
> */
> - old_status = atomic_cmpxchg(&pfdev->js->queue[j].status,
> - PANFROST_QUEUE_STATUS_STARTING,
> - PANFROST_QUEUE_STATUS_FAULT_PENDING);
> - if (old_status == PANFROST_QUEUE_STATUS_ACTIVE)
> - drm_sched_fault(&pfdev->js->queue[j].sched);
> + if (panfrost_exception_needs_reset(pfdev, js_status)) {
> + /*
> + * When the queue is being restarted we don't report
> + * faults directly to avoid races between the timeout
> + * and reset handlers. panfrost_scheduler_start() will
> + * call drm_sched_fault() after the queue has been
> + * started if status == FAULT_PENDING.
> + */
> + old_status = atomic_cmpxchg(&pfdev->js->queue[j].status,
> + PANFROST_QUEUE_STATUS_STARTING,
> + PANFROST_QUEUE_STATUS_FAULT_PENDING);
> + if (old_status == PANFROST_QUEUE_STATUS_ACTIVE)
> + drm_sched_fault(&pfdev->js->queue[j].sched);
> + } else {
> + dma_fence_set_error(pfdev->jobs[j]->done_fence,
> + panfrost_exception_to_error(js_status));
As in the previous patch - at the moment a status of STOPPED or
TERMINATED shouldn't actually happen. But the next patch is about to
change that! TERMINATED should definitely cause an error on the fence.
Steve
> + status |= JOB_INT_MASK_DONE(j);
> + }
> }
>
> if (status & JOB_INT_MASK_DONE(j)) {
>
