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Message-Id: <20251215171453.2506348-7-lukas.zapolskas@arm.com>
Date: Mon, 15 Dec 2025 17:14:52 +0000
From: Lukas Zapolskas <lukas.zapolskas@....com>
To: Boris Brezillon <boris.brezillon@...labora.com>,
Liviu Dudau <liviu.dudau@....com>,
Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>,
Thomas Zimmermann <tzimmermann@...e.de>,
David Airlie <airlied@...il.com>,
Simona Vetter <simona@...ll.ch>,
Adrián Larumbe <adrian.larumbe@...labora.com>
Cc: nd@....com,
dri-devel@...ts.freedesktop.org,
linux-kernel@...r.kernel.org,
Mihail Atanassov <mihail.atanassov@....com>,
Lukas Zapolskas <lukas.zapolskas@....com>
Subject: [PATCH v6 6/7] drm/panthor: Add suspend, resume and reset handling
The sampler must disable and re-enable counter sampling around
suspends, and must re-program the FW interface after a reset to
avoid losing data.
Signed-off-by: Lukas Zapolskas <lukas.zapolskas@....com>
---
drivers/gpu/drm/panthor/panthor_device.c | 7 ++-
drivers/gpu/drm/panthor/panthor_perf.c | 71 ++++++++++++++++++++++++
drivers/gpu/drm/panthor/panthor_perf.h | 6 ++
3 files changed, 83 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index 3063ffbead45..e6e279d91eae 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -162,6 +162,7 @@ static void panthor_device_reset_work(struct work_struct *work)
if (!drm_dev_enter(&ptdev->base, &cookie))
return;
+ panthor_perf_pre_reset(ptdev);
panthor_sched_pre_reset(ptdev);
panthor_fw_pre_reset(ptdev, true);
panthor_mmu_pre_reset(ptdev);
@@ -171,6 +172,7 @@ static void panthor_device_reset_work(struct work_struct *work)
ret = panthor_fw_post_reset(ptdev);
atomic_set(&ptdev->reset.pending, 0);
panthor_sched_post_reset(ptdev, ret != 0);
+ panthor_perf_post_reset(ptdev);
drm_dev_exit(cookie);
if (ret) {
@@ -549,8 +551,10 @@ int panthor_device_resume(struct device *dev)
ret = panthor_device_resume_hw_components(ptdev);
}
- if (!ret)
+ if (!ret) {
panthor_sched_resume(ptdev);
+ panthor_perf_resume(ptdev);
+ }
drm_dev_exit(cookie);
@@ -614,6 +618,7 @@ int panthor_device_suspend(struct device *dev)
/* We prepare everything as if we were resetting the GPU.
* The end of the reset will happen in the resume path though.
*/
+ panthor_perf_suspend(ptdev);
panthor_sched_suspend(ptdev);
panthor_fw_suspend(ptdev);
panthor_mmu_suspend(ptdev);
diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c
index e8f26805fe3a..208f93d516d4 100644
--- a/drivers/gpu/drm/panthor/panthor_perf.c
+++ b/drivers/gpu/drm/panthor/panthor_perf.c
@@ -1894,6 +1894,53 @@ void panthor_perf_session_destroy(struct panthor_file *pfile, struct panthor_per
}
}
+/**
+ * panthor_perf_suspend - Prepare the performance counter subsystem for system suspend.
+ * @ptdev: Panthor device.
+ *
+ * Indicate to the performance counters that the system is suspending.
+ *
+ * This function must not be used to handle MCU power state transitions: just before MCU goes
+ * from on to any inactive state, an automatic sample will be performed by the firmware, and
+ * the performance counter firmware state will be restored on warm boot.
+ *
+ */
+void panthor_perf_suspend(struct panthor_device *ptdev)
+{
+ struct panthor_perf *perf = ptdev->perf;
+ int ret;
+
+ if (!perf)
+ return;
+
+ ret = sampler_disable(&perf->sampler);
+
+ if (ret)
+ drm_warn(&ptdev->base, "Could not stop sampling before suspend, err = %d", ret);
+}
+
+/**
+ * panthor_perf_resume - Resume the performance counter subsystem after system resumption.
+ * @ptdev: Panthor device.
+ *
+ * Indicate to the performance counters that the system has resumed. This must not be used
+ * to handle MCU state transitions, for the same reasons as detailed in the kerneldoc for
+ * @panthor_perf_suspend.
+ */
+void panthor_perf_resume(struct panthor_device *ptdev)
+{
+ struct panthor_perf *perf = ptdev->perf;
+ int ret;
+
+ if (!perf)
+ return;
+
+ ret = sampler_enable(&perf->sampler);
+
+ if (ret)
+ drm_warn(&ptdev->base, "Could not resume sampling, err = %d", ret);
+}
+
/**
* panthor_perf_unplug - Terminate the performance counter subsystem.
* @ptdev: Panthor device.
@@ -1927,3 +1974,27 @@ void panthor_perf_unplug(struct panthor_device *ptdev)
ptdev->perf = NULL;
}
+
+void panthor_perf_pre_reset(struct panthor_device *ptdev)
+{
+ struct panthor_perf_sampler *sampler;
+
+ if (drm_WARN_ON_ONCE(&ptdev->base, !ptdev->perf))
+ return;
+
+ sampler = &ptdev->perf->sampler;
+
+ sampler_disable(sampler);
+}
+
+void panthor_perf_post_reset(struct panthor_device *ptdev)
+{
+ struct panthor_perf_sampler *sampler;
+
+ if (drm_WARN_ON_ONCE(&ptdev->base, !ptdev->perf))
+ return;
+
+ sampler = &ptdev->perf->sampler;
+
+ sampler_enable(sampler);
+}
diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h
index 5a14854368eb..1044b0a1cfaa 100644
--- a/drivers/gpu/drm/panthor/panthor_perf.h
+++ b/drivers/gpu/drm/panthor/panthor_perf.h
@@ -14,6 +14,8 @@ struct panthor_file;
struct panthor_perf;
int panthor_perf_init(struct panthor_device *ptdev);
+void panthor_perf_suspend(struct panthor_device *ptdev);
+void panthor_perf_resume(struct panthor_device *ptdev);
void panthor_perf_unplug(struct panthor_device *ptdev);
int panthor_perf_session_setup(struct drm_file *file, struct panthor_perf *perf,
@@ -30,5 +32,9 @@ void panthor_perf_session_destroy(struct panthor_file *pfile, struct panthor_per
void panthor_perf_report_irq(struct panthor_device *ptdev, u32 status);
+void panthor_perf_pre_reset(struct panthor_device *ptdev);
+
+void panthor_perf_post_reset(struct panthor_device *ptdev);
+
#endif /* __PANTHOR_PERF_H__ */
--
2.33.0.dirty
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