github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 01:55:51 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

drm/v3d: Flush MMU TLB and cache during runtime resume

Browse Source 
v3d_mmu_set_page_table() ends by calling v3d_mmu_flush_all() to flush the
MMU cache and clear the TLB after reprogramming V3D_MMU_PT_PA_BASE.
v3d_mmu_flush_all() is gated by pm_runtime_get_if_active(), which returns
0 unless runtime_status == RPM_ACTIVE.

v3d_mmu_set_page_table() is called from two paths that *know* V3D is
reachable, but where the runtime PM status might be wrong:

  1. v3d_power_resume(): the runtime resume callback itself, where
     runtime_status is RPM_RESUMING.

  2. v3d_reset(): called from the DRM scheduler timeout handler with the
     hung job's pm_runtime reference held, so RPM_ACTIVE, but here we
     don't need to take an extra reference for the duration of the flush
     either.

In the first case pm_runtime_get_if_active() returns 0, the flush is
silently skipped, and V3D resumes executing with whatever MMUC/TLB state
happened to survive the last reset. This can leave stale translations
live across runtime PM cycles, manifesting as random GPU hangs.

Split the actual flush sequence into a helper that does the writes
unconditionally, and have v3d_mmu_set_page_table() call it directly.

Fixes: 458f2a712a ("drm/v3d: Introduce Runtime Power Management")
Link: https://patch.msgid.link/20260530-v3d-fix-rpi4-freezes-v1-2-c2c8307da6ce@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
This commit is contained in:
Maíra Canal 2026-05-30 15:37:43 -03:00
parent f412fe573b
commit 257adf5ea6
No known key found for this signature in database
GPG Key ID: 3FF30E8A7688FAAA
1 changed files with 22 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/gpu/drm/v3d/v3d_mmu.c
View File

@ -37,13 +37,14 @@ static bool v3d_mmu_is_aligned(u32 page, u32 page_address, size_t alignment)
IS_ALIGNED(page_address, alignment >> V3D_MMU_PAGE_SHIFT);
}
int v3d_mmu_flush_all(struct v3d_dev *v3d)
/*
* Issue the MMUC flush and TLB clear unconditionally. The caller must
* already know that V3D is reachable. In particular, this is used from
* the runtime resume callback.
*/
static int v3d_mmu_flush_all_locked(struct v3d_dev *v3d)
{
int ret = 0;
/* Flush the PTs only if we're already awake */
if (!pm_runtime_get_if_active(v3d->drm.dev))
return 0;
int ret;
V3D_WRITE(V3D_MMUC_CONTROL, V3D_MMUC_CONTROL_FLUSH |
V3D_MMUC_CONTROL_ENABLE);
@ -52,7 +53,7 @@ int v3d_mmu_flush_all(struct v3d_dev *v3d)
V3D_MMUC_CONTROL_FLUSHING), 100);
if (ret) {
dev_err(v3d->drm.dev, "MMUC flush wait idle failed\n");
goto pm_put;
return ret;
}
V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL) |
@ -63,7 +64,19 @@ int v3d_mmu_flush_all(struct v3d_dev *v3d)
if (ret)
dev_err(v3d->drm.dev, "MMU TLB clear wait idle failed\n");
pm_put:
return ret;
}
int v3d_mmu_flush_all(struct v3d_dev *v3d)
{
int ret;
/* Flush the PTs only if we're already awake */
if (!pm_runtime_get_if_active(v3d->drm.dev))
return 0;
ret = v3d_mmu_flush_all_locked(v3d);
v3d_pm_runtime_put(v3d);
return ret;
}
@ -85,7 +98,7 @@ int v3d_mmu_set_page_table(struct v3d_dev *v3d)
V3D_MMU_ILLEGAL_ADDR_ENABLE);
V3D_WRITE(V3D_MMUC_CONTROL, V3D_MMUC_CONTROL_ENABLE);
return v3d_mmu_flush_all(v3d);
return v3d_mmu_flush_all_locked(v3d);
}
void v3d_mmu_insert_ptes(struct v3d_bo *bo)