From 57d4e26717b030fd794df3534e6b2e806eb761e4 Mon Sep 17 00:00:00 2001
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Date: Thu, 9 Nov 2023 11:25:38 +0100
Subject: [PATCH] drm/panfrost: Perform hard reset to recover GPU if soft reset
fails
Even though soft reset should ideally never fail, during development of
some power management features I managed to get some bits wrong: this
resulted in GPU soft reset failures, where the GPU was never able to
recover, not even after suspend/resume cycles, meaning that the only
way to get functionality back was to reboot the machine.
Perform a hard reset after a soft reset failure to be able to recover
the GPU during runtime (so, without any machine reboot).
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231109102543.42971-2-angelogioacchino.delregno@collabora.com
---
drivers/gpu/drm/panfrost/panfrost_gpu.c | 13 ++++++++++---
drivers/gpu/drm/panfrost/panfrost_regs.h | 1 +
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c
index 97f097ee5c1da..c9469bf7770a4 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gpu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c
@@ -60,14 +60,21 @@ int panfrost_gpu_soft_reset(struct panfrost_device *pfdev)
gpu_write(pfdev, GPU_INT_MASK, 0);
gpu_write(pfdev, GPU_INT_CLEAR, GPU_IRQ_RESET_COMPLETED);
- gpu_write(pfdev, GPU_CMD, GPU_CMD_SOFT_RESET);
+ gpu_write(pfdev, GPU_CMD, GPU_CMD_SOFT_RESET);
ret = readl_relaxed_poll_timeout(pfdev->iomem + GPU_INT_RAWSTAT,
val, val & GPU_IRQ_RESET_COMPLETED, 100, 10000);
if (ret) {
- dev_err(pfdev->dev, "gpu soft reset timed out\n");
- return ret;
+ dev_err(pfdev->dev, "gpu soft reset timed out, attempting hard reset\n");
+
+ gpu_write(pfdev, GPU_CMD, GPU_CMD_HARD_RESET);
+ ret = readl_relaxed_poll_timeout(pfdev->iomem + GPU_INT_RAWSTAT, val,
+ val & GPU_IRQ_RESET_COMPLETED, 100, 10000);
+ if (ret) {
+ dev_err(pfdev->dev, "gpu hard reset timed out\n");
+ return ret;
+ }
}
gpu_write(pfdev, GPU_INT_CLEAR, GPU_IRQ_MASK_ALL);
diff --git a/drivers/gpu/drm/panfrost/panfrost_regs.h b/drivers/gpu/drm/panfrost/panfrost_regs.h
index 55ec807550b3f..c25743b05c551 100644
--- a/drivers/gpu/drm/panfrost/panfrost_regs.h
+++ b/drivers/gpu/drm/panfrost/panfrost_regs.h
@@ -44,6 +44,7 @@
GPU_IRQ_MULTIPLE_FAULT)
#define GPU_CMD 0x30
#define GPU_CMD_SOFT_RESET 0x01
+#define GPU_CMD_HARD_RESET 0x02
#define GPU_CMD_PERFCNT_CLEAR 0x03
#define GPU_CMD_PERFCNT_SAMPLE 0x04
#define GPU_CMD_CYCLE_COUNT_START 0x05
--
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