Message ID | 20240718-mtk-cmdq-fixup-v2-1-f6bb3c052a60@mediatek.com (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | [v2] mailbox: mtk-cmdq: Move devm_mbox_controller_register() after devm_pm_runtime_enable() | expand |
Il 18/07/24 10:38, Jason-JH.Lin via B4 Relay ha scritto: > From: "Jason-JH.Lin" <jason-jh.lin@mediatek.com> > > 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> > --- > 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(). > > Change-Id: I4f0e68eac5186fe8041ea2f16c8e852d52d71cb0 > --- > Changes in v2: > - Change to move the calling sequence of devm_mbox_controller_register() > and devm_pm_runtime_enable(). > - Link to v1: https://lore.kernel.org/r/20240613150626.25280-1-jason-jh.lin@mediatek.com > --- > drivers/mailbox/mtk-cmdq-mailbox.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c > index f1dfce9e27f5..002003c3970a 100644 > --- a/drivers/mailbox/mtk-cmdq-mailbox.c > +++ b/drivers/mailbox/mtk-cmdq-mailbox.c > @@ -370,6 +370,8 @@ static void cmdq_remove(struct platform_device *pdev) > { > struct cmdq *cmdq = platform_get_drvdata(pdev); > > + devm_mbox_controller_unregister(&pdev->dev, &cmdq->mbox); ...if you moved devm_mbox_controller_register() after devm_pm_runtime_enable(), this means that the teardown sequence will disable pm runtime after unregistering the mbox controller, so why do you need to call devm_mbox_controller_unregister() manually here? Cheers, Angelo > + > if (cmdq->pdata->sw_ddr_en) > cmdq_sw_ddr_enable(cmdq, false); > > @@ -689,12 +691,6 @@ static int cmdq_probe(struct platform_device *pdev) > 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)); > @@ -722,6 +718,12 @@ static int cmdq_probe(struct platform_device *pdev) > pm_runtime_set_autosuspend_delay(dev, CMDQ_MBOX_AUTOSUSPEND_DELAY_MS); > pm_runtime_use_autosuspend(dev); > > + 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; > } > > > --- > base-commit: 797012914d2d031430268fe512af0ccd7d8e46ef > change-id: 20240718-mtk-cmdq-fixup-40379650e96b > > Best regards,
Hi Angelo, Thanks for the reviews. [snip] > > --- > > drivers/mailbox/mtk-cmdq-mailbox.c | 14 ++++++++------ > > 1 file changed, 8 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c > > b/drivers/mailbox/mtk-cmdq-mailbox.c > > index f1dfce9e27f5..002003c3970a 100644 > > --- a/drivers/mailbox/mtk-cmdq-mailbox.c > > +++ b/drivers/mailbox/mtk-cmdq-mailbox.c > > @@ -370,6 +370,8 @@ static void cmdq_remove(struct platform_device > > *pdev) > > { > > struct cmdq *cmdq = platform_get_drvdata(pdev); > > > > + devm_mbox_controller_unregister(&pdev->dev, &cmdq->mbox); > > ...if you moved devm_mbox_controller_register() after > devm_pm_runtime_enable(), > this means that the teardown sequence will disable pm runtime after > unregistering > the mbox controller, so why do you need to call > devm_mbox_controller_unregister() > manually here? > Since this is the first time I use b4 --manul-rerell to the v1 path, I forgot to remove the change in v1. I'll remove this and send v3 soon. Regards, Jason-JH.Lin > Cheers, > Angelo
diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c index f1dfce9e27f5..002003c3970a 100644 --- a/drivers/mailbox/mtk-cmdq-mailbox.c +++ b/drivers/mailbox/mtk-cmdq-mailbox.c @@ -370,6 +370,8 @@ static void cmdq_remove(struct platform_device *pdev) { struct cmdq *cmdq = platform_get_drvdata(pdev); + devm_mbox_controller_unregister(&pdev->dev, &cmdq->mbox); + if (cmdq->pdata->sw_ddr_en) cmdq_sw_ddr_enable(cmdq, false); @@ -689,12 +691,6 @@ static int cmdq_probe(struct platform_device *pdev) 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)); @@ -722,6 +718,12 @@ static int cmdq_probe(struct platform_device *pdev) pm_runtime_set_autosuspend_delay(dev, CMDQ_MBOX_AUTOSUSPEND_DELAY_MS); pm_runtime_use_autosuspend(dev); + 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; }