From 3aa0a80fc692c9959c261f4c5bfe9c23ddd90562 Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@collabora.com>
Date: Fri, 5 Feb 2021 12:17:55 +0100
Subject: [PATCH] drm/panfrost: Clear MMU irqs before handling the fault
Git-commit: 3aa0a80fc692c9959c261f4c5bfe9c23ddd90562
Patch-mainline: v5.13-rc1
References: git-fixes

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>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210205111757.585248-2-boris.brezillon@collabora.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 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;
 	}
 
-- 
2.26.2