drm/amdgpu/gmc7: Delegate VM faults to soft IRQ handler ring

On old GPUs, it may be an issue that handling the interrupts from
VM faults is too slow and the interrupt handler (IH) ring may
overflow, which can cause an eventual hang.

Delegate the processing of all VM faults to the soft
IRQ handler ring.

As a result, we spend much less time in the IRQ handler that
interacts with the HW IH ring, which significantly reduces the
chance of hangs/reboots.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index 0e5e54d0a9a5b0796c14a26401b3641a69093471..fbd0bf147f50c87e67f51f0ee743799521e962e4 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -1261,6 +1261,12 @@ static int gmc_v7_0_process_interrupt(struct amdgpu_device *adev,
 {
        u32 addr, status, mc_client, vmid;
 
+       /* Delegate to the soft IRQ handler ring */
+       if (adev->irq.ih_soft.enabled && entry->ih != &adev->irq.ih_soft) {
+               amdgpu_irq_delegate(adev, entry, 4);
+               return 1;
+       }
+
        addr = RREG32(mmVM_CONTEXT1_PROTECTION_FAULT_ADDR);
        status = RREG32(mmVM_CONTEXT1_PROTECTION_FAULT_STATUS);
        mc_client = RREG32(mmVM_CONTEXT1_PROTECTION_FAULT_MCCLIENT);