From 00bcc23a0371c0b7ff1fb4eaa6f27ed491e01dd1 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Fri, 4 Apr 2025 10:09:32 +0200 Subject: [PATCH] drm/panthor: Let IRQ handlers clear the interrupts themselves MMU handler needs to be in control of the job interrupt clears because clearing the interrupt also unblocks the writer/reader that triggered the fault, and we don't want it to be unblocked until we've had a chance to process the IRQ. Since clearing the clearing is just one line, let's make it explicit instead of doing it in the generic code path. Note that this commit changes the existing behavior in that the MMU COMPLETED irqs are no longer cleared, which is fine because they are masked, so we're not risking an interrupt flood. Changes in v3: - Mention the fact we no longer clear MMU COMPLETED irqs - Add Liviu's R-b Changes in v2: - Move the MMU_INT_CLEAR around Reviewed-by: Liviu Dudau Reviewed-by: Steven Price Link: https://lore.kernel.org/r/20250404080933.2912674-5-boris.brezillon@collabora.com Signed-off-by: Boris Brezillon --- drivers/gpu/drm/panthor/panthor_device.h | 2 -- drivers/gpu/drm/panthor/panthor_fw.c | 2 ++ drivers/gpu/drm/panthor/panthor_gpu.c | 2 ++ drivers/gpu/drm/panthor/panthor_mmu.c | 7 +++++++ 4 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h index fb9737b5452e..6905e34cbf90 100644 --- a/drivers/gpu/drm/panthor/panthor_device.h +++ b/drivers/gpu/drm/panthor/panthor_device.h @@ -415,8 +415,6 @@ static irqreturn_t panthor_ ## __name ## _irq_threaded_handler(int irq, void *da if (!status) \ break; \ \ - gpu_write(ptdev, __reg_prefix ## _INT_CLEAR, status); \ - \ __handler(ptdev, status); \ ret = IRQ_HANDLED; \ } \ diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c index 622c36b629c3..36f1034839c2 100644 --- a/drivers/gpu/drm/panthor/panthor_fw.c +++ b/drivers/gpu/drm/panthor/panthor_fw.c @@ -1010,6 +1010,8 @@ static void panthor_fw_init_global_iface(struct panthor_device *ptdev) static void panthor_job_irq_handler(struct panthor_device *ptdev, u32 status) { + gpu_write(ptdev, JOB_INT_CLEAR, status); + if (!ptdev->fw->booted && (status & JOB_INT_GLOBAL_IF)) ptdev->fw->booted = true; diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c index 72e41e6b8b7a..cb7a335e07d7 100644 --- a/drivers/gpu/drm/panthor/panthor_gpu.c +++ b/drivers/gpu/drm/panthor/panthor_gpu.c @@ -145,6 +145,8 @@ static void panthor_gpu_init_info(struct panthor_device *ptdev) static void panthor_gpu_irq_handler(struct panthor_device *ptdev, u32 status) { + gpu_write(ptdev, GPU_INT_CLEAR, status); + if (status & GPU_IRQ_FAULT) { u32 fault_status = gpu_read(ptdev, GPU_FAULT_STATUS); u64 address = gpu_read64(ptdev, GPU_FAULT_ADDR); diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index c2da51b684d9..bd09925a44d7 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -1686,6 +1686,13 @@ static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status) access_type, access_type_name(ptdev, fault_status), source_id); + /* We don't handle VM faults at the moment, so let's just clear the + * interrupt and let the writer/reader crash. + * Note that COMPLETED irqs are never cleared, but this is fine + * because they are always masked. + */ + gpu_write(ptdev, MMU_INT_CLEAR, mask); + /* Ignore MMU interrupts on this AS until it's been * re-enabled. */