Re: [PATCH] mailbox: mtk-cmdq: Add unregister mailbox controller in cmdq_remove()

[AngeloGioacchino Del Regno]

Il 18/06/24 05:28, Jason-JH Lin (林睿祥) ha scritto:
> Hi Angelo,
>
> On Fri, 2024-06-14 at 00:52 +0800, Jason-JH.Lin wrote:
> > Hi Angelo,
> >
> > On Thu, 2024-06-13 at 17:10 +0200, AngeloGioacchino Del Regno wrote:
> > > Il 13/06/24 17:06, Jason-JH.Lin ha scritto:
> > > > Add unregister mailbox controller in cmdq_remove to fix cmdq
> > > > unbind
> > > > WARN_ON message from pm_runtime_get_sync() in
> > > > cmdq_mbox_shutdown().
> > > >
> > > > Fixes: 623a6143a845 ("mailbox: mediatek: Add Mediatek CMDQ
> > > > driver")
> > > > Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> > >
> > > Hello,
> > >
> > > I think you forgot about...
> https://lore.kernel.org/all/6fcd48b14e865c25e6db7559fe6b946537bfa0ce.camel@xxxxxxxxxxxx/
> > >
> >
> > I'll send this series next week after testing it.
> >
> >
> > > ...as that would also resolve this one without any hacks.
> >
> > I thought it was another problem, so I sent this patch.
> >
> > After looking to the kerneldoc of devm_mbox_controller_unregister(),
> > I
> > found that it's not necessary to call this anywhere.
> >
> > I'll drop this patch. Thanks for the review.
>
> I found that the series of "Move pm_runimte_get and put to
> mbox_chan_ops API" can not fix this unbind crash issue.
>
> It seems they are 2 different issues.
>
> So I think calling devm_mbox_controller_unregister() in cmdq_remove()
> can ensure the CMDQ device is not removed and be paired to
> cmdq_probe().

Can you please paste the stack trace of that warning that you're seeing when
calling cmdq_remove()?

I'm not convinced that this is the best solution - it might be, but I have
a hunch that there might be a better way to address this issue.

Thanks!
Angelo

> Regards,
> Jason-JH.Lin
>
> > Regards,
> > Jason-JH.Lin
> >
> > > Cheers,
> > > Angelo
> > >
> > > > ---
> > > >    drivers/mailbox/mtk-cmdq-mailbox.c | 2 ++
> > > >    1 file changed, 2 insertions(+)
> > > >
> > > > diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c
> > > > b/drivers/mailbox/mtk-cmdq-mailbox.c
> > > > index 4aa394e91109..1399e18a39a4 100644
> > > > --- a/drivers/mailbox/mtk-cmdq-mailbox.c
> > > > +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> > > > @@ -371,6 +371,8 @@ 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);
> > > >