On 28/06/2021 08:42, Boris Brezillon wrote:
> This should avoid switching to interrupt context when the GPU is under
> heavy use.
>
> v3:
> * Don't take the job_lock in panfrost_job_handle_irq()
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
I thought I'd already reviewed this one, but anyway:
Reviewed-by: Steven Price <steven.price@xxxxxxx>
> ---
> drivers/gpu/drm/panfrost/panfrost_job.c | 53 ++++++++++++++++++-------
> 1 file changed, 38 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index be8f68f63974..e0c479e67304 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -470,19 +470,12 @@ static const struct drm_sched_backend_ops panfrost_sched_ops = {
> .free_job = panfrost_job_free
> };
>
> -static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> +static void panfrost_job_handle_irq(struct panfrost_device *pfdev, u32 status)
> {
> - struct panfrost_device *pfdev = data;
> - u32 status = job_read(pfdev, JOB_INT_STAT);
> int j;
>
> dev_dbg(pfdev->dev, "jobslot irq status=%x\n", status);
>
> - if (!status)
> - return IRQ_NONE;
> -
> - pm_runtime_mark_last_busy(pfdev->dev);
> -
> for (j = 0; status; j++) {
> u32 mask = MK_JS_MASK(j);
>
> @@ -519,7 +512,6 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> if (status & JOB_INT_MASK_DONE(j)) {
> struct panfrost_job *job;
>
> - spin_lock(&pfdev->js->job_lock);
> job = pfdev->jobs[j];
> /* Only NULL if job timeout occurred */
> if (job) {
> @@ -531,21 +523,49 @@ static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> dma_fence_signal_locked(job->done_fence);
> pm_runtime_put_autosuspend(pfdev->dev);
> }
> - spin_unlock(&pfdev->js->job_lock);
> }
>
> status &= ~mask;
> }
> +}
>
> +static irqreturn_t panfrost_job_irq_handler_thread(int irq, void *data)
> +{
> + struct panfrost_device *pfdev = data;
> + u32 status = job_read(pfdev, JOB_INT_RAWSTAT);
> +
> + while (status) {
> + pm_runtime_mark_last_busy(pfdev->dev);
> +
> + spin_lock(&pfdev->js->job_lock);
> + panfrost_job_handle_irq(pfdev, status);
> + spin_unlock(&pfdev->js->job_lock);
> + status = job_read(pfdev, JOB_INT_RAWSTAT);
> + }
> +
> + job_write(pfdev, JOB_INT_MASK,
> + GENMASK(16 + NUM_JOB_SLOTS - 1, 16) |
> + GENMASK(NUM_JOB_SLOTS - 1, 0));
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t panfrost_job_irq_handler(int irq, void *data)
> +{
> + struct panfrost_device *pfdev = data;
> + u32 status = job_read(pfdev, JOB_INT_STAT);
> +
> + if (!status)
> + return IRQ_NONE;
> +
> + job_write(pfdev, JOB_INT_MASK, 0);
> + return IRQ_WAKE_THREAD;
> +}
> +
> static void panfrost_reset(struct work_struct *work)
> {
> struct panfrost_device *pfdev = container_of(work,
> struct panfrost_device,
> reset.work);
> - unsigned long flags;
> unsigned int i;
> bool cookie;
>
> @@ -575,7 +595,7 @@ static void panfrost_reset(struct work_struct *work)
> /* All timers have been stopped, we can safely reset the pending state. */
> atomic_set(&pfdev->reset.pending, 0);
>
> - spin_lock_irqsave(&pfdev->js->job_lock, flags);
> + spin_lock(&pfdev->js->job_lock);
> for (i = 0; i < NUM_JOB_SLOTS; i++) {
> if (pfdev->jobs[i]) {
> pm_runtime_put_noidle(pfdev->dev);
> @@ -583,7 +603,7 @@ static void panfrost_reset(struct work_struct *work)
> pfdev->jobs[i] = NULL;
> }
> }
> - spin_unlock_irqrestore(&pfdev->js->job_lock, flags);
> + spin_unlock(&pfdev->js->job_lock);
>
> panfrost_device_reset(pfdev);
>
> @@ -610,8 +630,11 @@ int panfrost_job_init(struct panfrost_device *pfdev)
> if (irq <= 0)
> return -ENODEV;
>
> - ret = devm_request_irq(pfdev->dev, irq, panfrost_job_irq_handler,
> - IRQF_SHARED, KBUILD_MODNAME "-job", pfdev);
> + ret = devm_request_threaded_irq(pfdev->dev, irq,
> + panfrost_job_irq_handler,
> + panfrost_job_irq_handler_thread,
> + IRQF_SHARED, KBUILD_MODNAME "-job",
> + pfdev);
> if (ret) {
> dev_err(pfdev->dev, "failed to request job irq");
> return ret;
>
