This is a note to let you know that I've just added the patch titled
iommu/sun50i: Fix reset release
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-sun50i-fix-reset-release.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4971a6748282eb23244d5ee4b7c10472e88a1961
Author: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Date: Tue Oct 25 18:54:11 2022 +0200
iommu/sun50i: Fix reset release
[ Upstream commit 9ad0c1252e84dbc664f0462707182245ed603237 ]
Reset signal is asserted by writing 0 to the corresponding locations of
masters we want to reset. So in order to deassert all reset signals, we
should write 1's to all locations.
Current code writes 1's to locations of masters which were just reset
which is good. However, at the same time it also writes 0's to other
locations and thus asserts reset signals of remaining masters. Fix code
by writing all 1's when we want to deassert all reset signals.
This bug was discovered when working with Cedrus (video decoder). When
it faulted, display went blank due to reset signal assertion.
Fixes: 4100b8c229b3 ("iommu: Add Allwinner H6 IOMMU driver")
Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Link: https://lore.kernel.org/r/20221025165415.307591-2-jernej.skrabec@xxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
index ea6db1341916..3dead4f91420 100644
--- a/drivers/iommu/sun50i-iommu.c
+++ b/drivers/iommu/sun50i-iommu.c
@@ -28,6 +28,7 @@
#include <linux/types.h>
#define IOMMU_RESET_REG 0x010
+#define IOMMU_RESET_RELEASE_ALL 0xffffffff
#define IOMMU_ENABLE_REG 0x020
#define IOMMU_ENABLE_ENABLE BIT(0)
@@ -905,7 +906,7 @@ static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
iommu_write(iommu, IOMMU_INT_CLR_REG, status);
iommu_write(iommu, IOMMU_RESET_REG, ~status);
- iommu_write(iommu, IOMMU_RESET_REG, status);
+ iommu_write(iommu, IOMMU_RESET_REG, IOMMU_RESET_RELEASE_ALL);
spin_unlock(&iommu->iommu_lock);
