netdev - Re: [PATCH 02/13] ALSA: hda_intel: Use always-managed version of pcim

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Message-ID: <6f3db65fe9a5dcd1a7a8d9bd5352ecb248ef57b1.camel@redhat.com>
Date: Wed, 23 Oct 2024 15:50:09 +0200
From: Philipp Stanner <pstanner@...hat.com>
To: Takashi Iwai <tiwai@...e.de>
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Subject: Re: [PATCH 02/13] ALSA: hda_intel: Use always-managed version of
 pcim_intx()

On Tue, 2024-10-22 at 16:08 +0200, Takashi Iwai wrote:
> On Tue, 15 Oct 2024 20:51:12 +0200,
> Philipp Stanner wrote:
> > 
> > pci_intx() is a hybrid function which can sometimes be managed
> > through
> > devres. To remove this hybrid nature from pci_intx(), it is
> > necessary to
> > port users to either an always-managed or a never-managed version.
> > 
> > hda_intel enables its PCI-Device with pcim_enable_device(). Thus,
> > it needs
> > the always-managed version.
> > 
> > Replace pci_intx() with pcim_intx().
> > 
> > Signed-off-by: Philipp Stanner <pstanner@...hat.com>
> > ---
> >  sound/pci/hda/hda_intel.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index b4540c5cd2a6..b44ca7b6e54f 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -786,7 +786,7 @@ static int azx_acquire_irq(struct azx *chip,
> > int do_disconnect)
> >  	}
> >  	bus->irq = chip->pci->irq;
> >  	chip->card->sync_irq = bus->irq;
> > -	pci_intx(chip->pci, !chip->msi);
> > +	pcim_intx(chip->pci, !chip->msi);
> >  	return 0;
> >  }
> >  
> 
> Hm, it's OK-ish to do this as it's practically same as what
> pci_intx()
> currently does.  But, the current code can be a bit inconsistent
> about
> the original intx value.  pcim_intx() always stores !enable to
> res->orig_intx unconditionally, and it means that the orig_intx value
> gets overridden at each time pcim_intx() gets called.

Yes.

> 
> Meanwhile, HD-audio driver does release and re-acquire the interrupt
> after disabling MSI when something goes wrong, and pci_intx() call
> above is a part of that procedure.  So, it can rewrite the
> res->orig_intx to another value by retry without MSI.  And after the
> driver removal, it'll lead to another state.

I'm not sure that I understand this paragraph completely. Still, could
a solution for the driver on the long-term just be to use pci_intx()?

> 
> In anyway, as it doesn't change the current behavior, feel free to
> take my ack for now:
> 
> Acked-by: Takashi Iwai <tiwai@...e.de>

Thank you,
P.

> 
> 
> thanks,
> 
> Takashi
>