From 9ad0c1252e84dbc664f0462707182245ed603237 Mon Sep 17 00:00:00 2001 From: Jernej Skrabec Date: Tue, 25 Oct 2022 18:54:11 +0200 Subject: [PATCH] iommu/sun50i: Fix reset release 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 Link: https://lore.kernel.org/r/20221025165415.307591-2-jernej.skrabec@gmail.com Signed-off-by: Joerg Roedel --- drivers/iommu/sun50i-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c index cd9b74ee24de..270204a6ec4a 100644 --- a/drivers/iommu/sun50i-iommu.c +++ b/drivers/iommu/sun50i-iommu.c @@ -27,6 +27,7 @@ #include #define IOMMU_RESET_REG 0x010 +#define IOMMU_RESET_RELEASE_ALL 0xffffffff #define IOMMU_ENABLE_REG 0x020 #define IOMMU_ENABLE_ENABLE BIT(0) @@ -893,7 +894,7 @@ 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);