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* [PATCH v5] drm/xe: Poll GT for C6 before D3
@ 2026-09-15 21:01 Vinay Belgaumkar
  2026-09-15 21:14 ` ✓ CI.KUnit: success for drm/xe: Poll GT for C6 before D3 (rev2) Patchwork
                   ` (4 more replies)
  0 siblings, 5 replies; 11+ messages in thread
From: Vinay Belgaumkar @ 2026-09-15 21:01 UTC (permalink / raw)
  To: intel-xe; +Cc: Vinay Belgaumkar, Badal Nilawar, Rodrigo Vivi

Ensure GT C6 state before D3 transition in runtime suspend flow.
This avoids the scenario where GT is being accessed after D3 state
is programmed. If the check for C6 fails, resume the device so it is
not stuck in an intermediate state.

v2: Force resume when we cancel suspend due to C6 check (Sashiko)
v3: Abort the suspend properly when idle check fails (Sashiko)
v4: Only check for C6 during suspend (Rodrigo). Have check in
xe_pci_runtime_suspend() instead of xe_pci_suspend().
v5: Don't checkfor PVC (Sashiko), rename function from_device_c6
to _device_idle

Cc: Badal Nilawar <badal.nilawar@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_idle.c | 36 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt_idle.h |  1 +
 drivers/gpu/drm/xe/xe_pci.c     | 13 +++++++++++-
 drivers/gpu/drm/xe/xe_pm.c      | 24 ++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_pm.h      |  1 +
 5 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_idle.c b/drivers/gpu/drm/xe/xe_gt_idle.c
index c208d7563e36..8242feede1dd 100644
--- a/drivers/gpu/drm/xe/xe_gt_idle.c
+++ b/drivers/gpu/drm/xe/xe_gt_idle.c
@@ -8,10 +8,12 @@
 #include <drm/drm_managed.h>
 
 #include <generated/xe_wa_oob.h>
+#include <linux/iopoll.h>
 #include "xe_force_wake.h"
 #include "xe_device.h"
 #include "xe_gt.h"
 #include "xe_gt_idle.h"
+#include "xe_gt_printk.h"
 #include "xe_gt_sysfs.h"
 #include "xe_guc_pc.h"
 #include "regs/xe_gt_regs.h"
@@ -451,3 +453,37 @@ int xe_gt_idle_disable_c6(struct xe_gt *gt)
 
 	return 0;
 }
+
+static int wait_for_gt_c6_state(struct xe_gt *gt, u32 timeout_ms)
+{
+	struct xe_guc_pc *pc = &gt->uc.guc.pc;
+	enum xe_gt_idle_state state;
+
+	return poll_timeout_us(state = gt->gtidle.idle_status(pc),
+			       state == GT_IDLE_C6,
+			       20,
+			       timeout_ms * USEC_PER_MSEC,
+			       false);
+}
+
+/**
+ * xe_gt_idle_wait_for_c6 - Poll for GT C6
+ * @gt: GT object
+ * @timeout_ms: wait time in ms
+ *
+ * This function waits for GT to enter C6.
+ *
+ * Return: 0 on success, -EAGAIN otherwise
+ */
+int xe_gt_idle_wait_for_c6(struct xe_gt *gt, u32 timeout_ms)
+{
+	if (IS_SRIOV_VF(gt_to_xe(gt)))
+		return 0;
+
+	if (wait_for_gt_c6_state(gt, timeout_ms)) {
+		xe_gt_dbg(gt, "GT is not in C6\n");
+		return -EAGAIN;
+	}
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/xe/xe_gt_idle.h b/drivers/gpu/drm/xe/xe_gt_idle.h
index 9c34a155e102..2c8e9adf4a68 100644
--- a/drivers/gpu/drm/xe/xe_gt_idle.h
+++ b/drivers/gpu/drm/xe/xe_gt_idle.h
@@ -18,5 +18,6 @@ void xe_gt_idle_enable_pg(struct xe_gt *gt);
 void xe_gt_idle_disable_pg(struct xe_gt *gt);
 int xe_gt_idle_pg_print(struct xe_gt *gt, struct drm_printer *p);
 u64 xe_gt_idle_residency_msec(struct xe_gt_idle *gtidle);
+int xe_gt_idle_wait_for_c6(struct xe_gt *gt, u32 timeout_ms);
 
 #endif /* _XE_GT_IDLE_H_ */
diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index ab4da1d9a9f1..379795ac5e7b 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -1381,7 +1381,7 @@ static int xe_pci_runtime_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct xe_device *xe = pdev_to_xe_device(pdev);
-	int err;
+	int err, ret;
 
 	/*
 	 * We hold an additional reference to the runtime PM to keep PF in D0
@@ -1396,6 +1396,17 @@ static int xe_pci_runtime_suspend(struct device *dev)
 	if (err)
 		return err;
 
+	err = xe_pm_check_device_idle(xe);
+	if (err) {
+		drm_dbg(&xe->drm, "Resuming - Device idle check failed!");
+		ret = xe_pm_runtime_resume(xe);
+		if (ret) {
+			drm_err(&xe->drm, "Resume failed after suspend was canceled");
+			return ret;
+		}
+		return err;
+	}
+
 	pci_save_state(pdev);
 
 	if (xe->d3cold.allowed) {
diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index f517bf453b54..f03a463d2a05 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -1030,6 +1030,30 @@ void xe_pm_d3cold_allowed_toggle(struct xe_device *xe)
 	mutex_unlock(&xe->d3cold.lock);
 }
 
+/**
+ * xe_pm_check_device_idle() - Check if all GTs are idle.
+ * @xe: xe device instance
+ *
+ * One of the ways to do this is to check for GT C6 state. This check
+ * will fail if some component is holding a forcewake, for example.
+ *
+ * Return: 0 on success, -EAGAIN on failure
+ */
+int xe_pm_check_device_idle(struct xe_device *xe)
+{
+	struct xe_gt *gt;
+	u8 id;
+
+	if (xe->info.platform == XE_PVC)
+		return 0;
+
+	for_each_gt(gt, xe, id)
+		if (xe_gt_idle_wait_for_c6(gt, 200))
+			return -EAGAIN;
+
+	return 0;
+}
+
 /**
  * xe_pm_module_init() - Perform xe_pm specific module initialization.
  *
diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
index 6d5ab09cb769..a4fdc9c5cb10 100644
--- a/drivers/gpu/drm/xe/xe_pm.h
+++ b/drivers/gpu/drm/xe/xe_pm.h
@@ -36,6 +36,7 @@ void xe_pm_d3cold_allowed_toggle(struct xe_device *xe);
 bool xe_rpm_reclaim_safe(const struct xe_device *xe);
 struct task_struct *xe_pm_read_callback_task(struct xe_device *xe);
 int xe_pm_block_on_suspend(struct xe_device *xe);
+int xe_pm_check_device_idle(struct xe_device *xe);
 void xe_pm_might_block_on_suspend(void);
 int xe_pm_module_init(void);
 
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
end of thread, other threads:[~2026-09-16 18:50 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-09-15 21:01 [PATCH v5] drm/xe: Poll GT for C6 before D3 Vinay Belgaumkar
2026-09-15 21:14 ` ✓ CI.KUnit: success for drm/xe: Poll GT for C6 before D3 (rev2) Patchwork
2026-09-15 21:20 ` [PATCH v5] drm/xe: Poll GT for C6 before D3 sashiko-bot
2026-09-16 12:21   ` Rodrigo Vivi
2026-09-16 18:50     ` Belgaumkar, Vinay
2026-09-15 21:51 ` ✓ Xe.CI.BAT: success for drm/xe: Poll GT for C6 before D3 (rev2) Patchwork
2026-09-16  4:04 ` ✓ Xe.CI.FULL: " Patchwork
2026-09-16 12:19 ` [PATCH v5] drm/xe: Poll GT for C6 before D3 Rodrigo Vivi
2026-09-16 15:05   ` Belgaumkar, Vinay
2026-09-16 15:44     ` Rodrigo Vivi
2026-09-16 17:06       ` Belgaumkar, Vinay

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