From 545d9d780262fcff6ed48dcd812a816cd88e5003 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Wed, 23 Dec 2020 21:35:13 +0100
Subject: [PATCH] drm/v3d: Don't clear MMU control bits on exception
MMU exception conditions are reported in the V3D_MMU_CTRL register as
write-1-to-clear (W1C) bits. The MMU interrupt handling code clears any
exceptions, but does so by masking out any other bits and writing the
result back. There are some important control bits in that register,
including MMU_ENABLE, so a safer approach is to simply write back the
value just read unaltered.
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/1608755714-18233-4-git-send-email-stefan.wahren@i2se.com
---
drivers/gpu/drm/v3d/v3d_irq.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/v3d/v3d_irq.c b/drivers/gpu/drm/v3d/v3d_irq.c
index 0be2eb7876bed..e714d5318f309 100644
--- a/drivers/gpu/drm/v3d/v3d_irq.c
+++ b/drivers/gpu/drm/v3d/v3d_irq.c
@@ -178,10 +178,7 @@ v3d_hub_irq(int irq, void *arg)
};
const char *client = "?";
- V3D_WRITE(V3D_MMU_CTL,
- V3D_READ(V3D_MMU_CTL) & (V3D_MMU_CTL_CAP_EXCEEDED |
- V3D_MMU_CTL_PT_INVALID |
- V3D_MMU_CTL_WRITE_VIOLATION));
+ V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL));
if (v3d->ver >= 41) {
axi_id = axi_id >> 5;
--
2.30.2