This is a note to let you know that I've just added the patch titled drm/panfrost: Clear MMU irqs before handling the fault to the 5.4-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: drm-panfrost-clear-mmu-irqs-before-handling-the-fault.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 3aa0a80fc692c9959c261f4c5bfe9c23ddd90562 Mon Sep 17 00:00:00 2001 From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> Date: Fri, 5 Feb 2021 12:17:55 +0100 Subject: drm/panfrost: Clear MMU irqs before handling the fault From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> commit 3aa0a80fc692c9959c261f4c5bfe9c23ddd90562 upstream. 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@xxxxxxxxxxxxxxx> Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations") Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> Reviewed-by: Steven Price <steven.price@xxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210205111757.585248-2-boris.brezillon@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -600,6 +600,8 @@ static irqreturn_t panfrost_mmu_irq_hand 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) @@ -623,8 +625,6 @@ static irqreturn_t panfrost_mmu_irq_hand access_type, access_type_name(pfdev, fault_status), source_id); - mmu_write(pfdev, MMU_INT_CLEAR, mask); - status &= ~mask; } Patches currently in stable-queue which might be from boris.brezillon@xxxxxxxxxxxxx are queue-5.4/drm-panfrost-don-t-try-to-map-pages-that-are-already-mapped.patch queue-5.4/drm-panfrost-clear-mmu-irqs-before-handling-the-fault.patch