There is no recovery mechanism in place yet to recover from mmu
faults for DPU. We can only prevent the faults by making sure there
is no misconfiguration.
Rate-limit the snapshot capture for mmu faults to once per
msm_kms_init_aspace() as that should be sufficient to capture
the snapshot for debugging otherwise there will be a lot of
dpu snapshots getting captured for the same fault which is
redundant and also might affect capturing even one snapshot
accurately.
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_kms.c | 6 +++++-
drivers/gpu/drm/msm/msm_kms.h | 3 +++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_kms.c b/drivers/gpu/drm/msm/msm_kms.c
index d5d3117259cf..90a333920c01 100644
--- a/drivers/gpu/drm/msm/msm_kms.c
+++ b/drivers/gpu/drm/msm/msm_kms.c
@@ -168,7 +168,10 @@ static int msm_kms_fault_handler(void *arg, unsigned long iova, int flags, void
{
struct msm_kms *kms = arg;
- msm_disp_snapshot_state(kms->dev);
+ if (!kms->fault_snapshot_capture) {
+ msm_disp_snapshot_state(kms->dev);
+ kms->fault_snapshot_capture++;
+ }
return -ENOSYS;
}
@@ -208,6 +211,7 @@ struct msm_gem_address_space *msm_kms_init_aspace(struct drm_device *dev)
mmu->funcs->destroy(mmu);
}
+ kms->fault_snapshot_capture = 0;
msm_mmu_set_fault_handler(aspace->mmu, kms, msm_kms_fault_handler);
return aspace;
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index 1e0c54de3716..240b39e60828 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -134,6 +134,9 @@ struct msm_kms {
int irq;
bool irq_requested;
+ /* rate limit the snapshot capture to once per attach */
+ int fault_snapshot_capture;
+
/* mapper-id used to request GEM buffer mapped for scanout: */
struct msm_gem_address_space *aspace;
--
2.44.0
