On 05/02/2026 21:31, Maíra Canal wrote:
The function vc4_save_hang_state() reads V3D registers to capture the
GPU state after a timeout, but it does so without holding a PM
reference. Wrap the register reads with vc4_v3d_pm_get/put() to ensure
the device is powered on while capturing hang state.
This patch and 11/11 maybe belong in a different series?
Regards,
Tvrtko
Signed-off-by: Maíra Canal <[email protected]>
---
drivers/gpu/drm/vc4/vc4_gem.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index
1aa54c49b033ac0c85e49988d7fbe9cbaa37b000..856b30c6d8a70f4a3b515ff892ce9d7de7de02ab
100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -207,6 +207,11 @@ vc4_save_hang_state(struct drm_device *dev)
spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ if (vc4_v3d_pm_get(vc4)) {
+ vc4_free_hang_state(dev, kernel_state);
+ return;
+ }
+
state->ct0ca = V3D_READ(V3D_CTNCA(0));
state->ct0ea = V3D_READ(V3D_CTNEA(0));
@@ -233,6 +238,8 @@ vc4_save_hang_state(struct drm_device *dev)
state->fdbgs = V3D_READ(V3D_FDBGS);
state->errstat = V3D_READ(V3D_ERRSTAT);
+ vc4_v3d_pm_put(vc4);
+
/* We need to turn purgeable BOs into unpurgeable ones so that
* userspace has a chance to dump the hang state before the kernel
* decides to purge those BOs.
