6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jason-JH.Lin jason-jh.lin@mediatek.com
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@mediatek.com Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Signed-off-by: Jassi Brar jassisinghbrar@gmail.com Signed-off-by: Bin Lan bin.lan.cn@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -605,18 +605,18 @@ 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->gce_num, cmdq->clocks));
cmdq_init(cmdq);
+ 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; }