6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wentong Wu <wentong.wu@xxxxxxxxx>
commit 9b5e045029d8bded4c6979874ed3abc347c1415c upstream.
The dynamically created mei client device (mei csi) is used as one V4L2
sub device of the whole video pipeline, and the V4L2 connection graph is
built by software node. The mei_stop() and mei_restart() will delete the
old mei csi client device and create a new mei client device, which will
cause the software node information saved in old mei csi device lost and
the whole video pipeline will be broken.
Removing mei_stop()/mei_restart() during system suspend/resume can fix
the issue above and won't impact hardware actual power saving logic.
Fixes: f6085a96c973 ("mei: vsc: Unregister interrupt handler for system suspend")
Cc: stable@xxxxxxxxxxxxxxx # for 6.8+
Reported-by: Hao Yao <hao.yao@xxxxxxxxx>
Signed-off-by: Wentong Wu <wentong.wu@xxxxxxxxx>
Reviewed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Tested-by: Jason Chen <jason.z.chen@xxxxxxxxx>
Tested-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240527123835.522384-1-wentong.wu@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/mei/platform-vsc.c | 39 +++++++++++++++------------------------
1 file changed, 15 insertions(+), 24 deletions(-)
--- a/drivers/misc/mei/platform-vsc.c
+++ b/drivers/misc/mei/platform-vsc.c
@@ -399,41 +399,32 @@ static void mei_vsc_remove(struct platfo
static int mei_vsc_suspend(struct device *dev)
{
- struct mei_device *mei_dev = dev_get_drvdata(dev);
- struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
+ struct mei_device *mei_dev;
+ int ret = 0;
- mei_stop(mei_dev);
+ mei_dev = dev_get_drvdata(dev);
+ if (!mei_dev)
+ return -ENODEV;
- mei_disable_interrupts(mei_dev);
+ mutex_lock(&mei_dev->device_lock);
- vsc_tp_free_irq(hw->tp);
+ if (!mei_write_is_idle(mei_dev))
+ ret = -EAGAIN;
- return 0;
+ mutex_unlock(&mei_dev->device_lock);
+
+ return ret;
}
static int mei_vsc_resume(struct device *dev)
{
- struct mei_device *mei_dev = dev_get_drvdata(dev);
- struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
- int ret;
-
- ret = vsc_tp_request_irq(hw->tp);
- if (ret)
- return ret;
-
- ret = mei_restart(mei_dev);
- if (ret)
- goto err_free;
+ struct mei_device *mei_dev;
- /* start timer if stopped in suspend */
- schedule_delayed_work(&mei_dev->timer_work, HZ);
+ mei_dev = dev_get_drvdata(dev);
+ if (!mei_dev)
+ return -ENODEV;
return 0;
-
-err_free:
- vsc_tp_free_irq(hw->tp);
-
- return ret;
}
static DEFINE_SIMPLE_DEV_PM_OPS(mei_vsc_pm_ops, mei_vsc_suspend, mei_vsc_resume);
