6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
commit a8bd68e4329f9a0ad1b878733e0f80be6a971649 upstream.
When mtk-cmdq unbinds, a WARN_ON message with condition
pm_runtime_get_sync() < 0 occurs.
According to the call tracei below:
cmdq_mbox_shutdown
mbox_free_channel
mbox_controller_unregister
__devm_mbox_controller_unregister
...
The root cause can be deduced to be calling pm_runtime_get_sync() after
calling pm_runtime_disable() as observed below:
1. CMDQ driver uses devm_mbox_controller_register() in cmdq_probe()
to bind the cmdq device to the mbox_controller, so
devm_mbox_controller_unregister() will automatically unregister
the device bound to the mailbox controller when the device-managed
resource is removed. That means devm_mbox_controller_unregister()
and cmdq_mbox_shoutdown() will be called after cmdq_remove().
2. CMDQ driver also uses devm_pm_runtime_enable() in cmdq_probe() after
devm_mbox_controller_register(), so that devm_pm_runtime_disable()
will be called after cmdq_remove(), but before
devm_mbox_controller_unregister().
To fix this problem, cmdq_probe() needs to move
devm_mbox_controller_register() after devm_pm_runtime_enable() to make
devm_pm_runtime_disable() be called after
devm_mbox_controller_unregister().
Fixes: 623a6143a845 ("mailbox: mediatek: Add Mediatek CMDQ driver")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Signed-off-by: Jassi Brar <jassisinghbrar@xxxxxxxxx>
Signed-off-by: Bin Lan <bin.lan.cn@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mailbox/mtk-cmdq-mailbox.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -623,12 +623,6 @@ static int cmdq_probe(struct platform_de
cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
}
- err = devm_mbox_controller_register(dev, &cmdq->mbox);
- if (err < 0) {
- dev_err(dev, "failed to register mailbox: %d\n", err);
- return err;
- }
-
platform_set_drvdata(pdev, cmdq);
WARN_ON(clk_bulk_prepare(cmdq->pdata->gce_num, cmdq->clocks));
@@ -642,6 +636,12 @@ static int cmdq_probe(struct platform_de
return err;
}
+ err = devm_mbox_controller_register(dev, &cmdq->mbox);
+ if (err < 0) {
+ dev_err(dev, "failed to register mailbox: %d\n", err);
+ return err;
+ }
+
return 0;
}
