[PATCH v2] drm/imagination: re-check firmware idle state before runtime suspend

[Baihui Liang]

pvr_power_device_idle() rejects runtime suspend while the firmware
hasn't reached ROGUE_FWIF_POW_IDLE. The PM core doesn't reschedule
idle notification after rejection, so no further pm_runtime_put()
arrives on an idle GPU and the device stays powered indefinitely.

Move the idle check into pvr_power_device_suspend() and return -EBUSY
after pm_runtime_mark_last_busy() so the PM core reschedules the
autosuspend timer and retries until the firmware is idle.

Signed-off-by: Baihui Liang <liangbaihui at linux.spacemit.com>
---
Changes in v2:
- Move the pvr_power_is_idle() check into pvr_power_device_suspend()
  and return -EBUSY after pm_runtime_mark_last_busy().
- Drop pvr_power_device_idle() and pass NULL in RUNTIME_PM_OPS().
- Link to v1: https://patch.msgid.link/20261029-img-pm-autosuspend-v1-1-26851840a34e@linux.spacemit.com
---
 drivers/gpu/drm/imagination/pvr_drv.c   |  2 +-
 drivers/gpu/drm/imagination/pvr_power.c | 22 ++++++++++++----------
 drivers/gpu/drm/imagination/pvr_power.h |  1 -
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
index 5c965ef0274..541351d4bb6 100644
--- a/drivers/gpu/drm/imagination/pvr_drv.c
+++ b/drivers/gpu/drm/imagination/pvr_drv.c
@@ -1516,7 +1516,7 @@ static const struct of_device_id dt_match[] = {
 MODULE_DEVICE_TABLE(of, dt_match);
 
 static const struct dev_pm_ops pvr_pm_ops = {
-	RUNTIME_PM_OPS(pvr_power_device_suspend, pvr_power_device_resume, pvr_power_device_idle)
+	RUNTIME_PM_OPS(pvr_power_device_suspend, pvr_power_device_resume, NULL)
 };
 
 static struct platform_driver pvr_driver = {
diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
index eb4b6ecdf4f..71267f714c7 100644
--- a/drivers/gpu/drm/imagination/pvr_power.c
+++ b/drivers/gpu/drm/imagination/pvr_power.c
@@ -378,6 +378,18 @@ pvr_power_device_suspend(struct device *dev)
 	if (!drm_dev_enter(drm_dev, &idx))
 		return -EIO;
 
+	if (READ_ONCE(pvr_dev->fw_dev.initialised) && !pvr_power_is_idle(pvr_dev)) {
+		/*
+		 * The firmware has not drained the GPU yet. Refresh last_busy so
+		 * the PM core reschedules the autosuspend and retries this callback
+		 * until the firmware becomes idle.
+		 */
+		pm_runtime_mark_last_busy(dev);
+		drm_dev_exit(idx);
+
+		return -EBUSY;
+	}
+
 	if (READ_ONCE(pvr_dev->fw_dev.initialised)) {
 		err = pvr_power_fw_disable(pvr_dev, false, true);
 		if (err)
@@ -427,16 +439,6 @@ pvr_power_device_resume(struct device *dev)
 	return err;
 }
 
-int
-pvr_power_device_idle(struct device *dev)
-{
-	struct platform_device *plat_dev = to_platform_device(dev);
-	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
-	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
-
-	return pvr_power_is_idle(pvr_dev) ? 0 : -EBUSY;
-}
-
 static int
 pvr_power_clear_error(struct pvr_device *pvr_dev)
 {
diff --git a/drivers/gpu/drm/imagination/pvr_power.h b/drivers/gpu/drm/imagination/pvr_power.h
index c34252bda07..7d8df45c7b1 100644
--- a/drivers/gpu/drm/imagination/pvr_power.h
+++ b/drivers/gpu/drm/imagination/pvr_power.h
@@ -18,7 +18,6 @@ bool pvr_power_is_idle(struct pvr_device *pvr_dev);
 
 int pvr_power_device_suspend(struct device *dev);
 int pvr_power_device_resume(struct device *dev);
-int pvr_power_device_idle(struct device *dev);
 
 int pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset);
 

---
base-commit: 067c5c24cef23d913b67eaaf71ae67e7169a6620
change-id: 20261029-img-pm-autosuspend-7772d83416f7

Best regards,
--  
Baihui Liang <liangbaihui at linux.spacemit.com>