From 2da20c92ce22e3e0356d0b3e3cdfc307bb24a1a0 Mon Sep 17 00:00:00 2001
From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Date: Mon, 7 Aug 2023 03:04:44 +0300
Subject: drm/panfrost: Sync IRQ by job's timeout handler
Panfrost IRQ handler may stuck for a long time, for example this happens
when there is a bad HDMI connection and HDMI handler takes a long time to
finish processing, holding Panfrost. Make Panfrost's job timeout handler
to sync IRQ before checking fence signal status in order to prevent
spurious job timeouts due to a slow IRQ processing.
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> # MediaTek MT8192 and MT8195 Chromebooks
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807000444.14926-1-dmitry.osipenko@collabora.com
---
drivers/gpu/drm/panfrost/panfrost_job.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
(limited to 'drivers')
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index dbc597ab46fb..a8b4827dc425 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -720,6 +720,22 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
if (dma_fence_is_signaled(job->done_fence))
return DRM_GPU_SCHED_STAT_NOMINAL;
+ /*
+ * Panfrost IRQ handler may take a long time to process an interrupt
+ * if there is another IRQ handler hogging the processing.
+ * For example, the HDMI encoder driver might be stuck in the IRQ
+ * handler for a significant time in a case of bad cable connection.
+ * In order to catch such cases and not report spurious Panfrost
+ * job timeouts, synchronize the IRQ handler and re-check the fence
+ * status.
+ */
+ synchronize_irq(pfdev->js->irq);
+
+ if (dma_fence_is_signaled(job->done_fence)) {
+ dev_warn(pfdev->dev, "unexpectedly high interrupt latency\n");
+ return DRM_GPU_SCHED_STAT_NOMINAL;
+ }
+
dev_err(pfdev->dev, "gpu sched timeout, js=%d, config=0x%x, status=0x%x, head=0x%x, tail=0x%x, sched_job=%p",
js,
job_read(pfdev, JS_CONFIG(js)),
--
cgit