Re: [PATCH 00/13] Remove implicit devres from pci_intx()

Philipp Stanner
2024-10-31T09:28:37Z

On Thu, 2024-10-31 at 10:19 +0100, Takashi Iwai wrote:
> On Wed, 30 Oct 2024 23:17:37 +0100,
> Bjorn Helgaas wrote:
> >
> > On Tue, Oct 15, 2024 at 08:51:10PM +0200, Philipp Stanner wrote:
> > > @Driver-Maintainers: Your driver might be touched by patch
> > > "Remove
> > > devres from pci_intx()". You might want to take a look.
> > >
> > > Changes since the RFC [1]:
> > >   - Add a patch deprecating pci{m}_intx(). (Heiner, Andy, Me)
> > >   - Add Acked-by's already given.
> > >   - Export pcim_intx() as a GPL function. (Alex)
> > >   - Drop patch for rts5280, since this driver will be removed
> > > quite
> > >     soon. (Philipp Hortmann, Greg)
> > >   - Use early-return in pci_intx_unmanaged() and pci_intx().
> > > (Andy)
> > >
> > > Hi all,
> > >
> > > this series removes a problematic feature from pci_intx(). That
> > > function
> > > sometimes implicitly uses devres for automatic cleanup. We should
> > > get
> > > rid of this implicit behavior.
> > >
> > > To do so, a pci_intx() version that is always-managed, and one
> > > that is
> > > never-managed are provided. Then, all pci_intx() users are ported
> > > to the
> > > version they need. Afterwards, pci_intx() can be cleaned up and
> > > the
> > > users of the never-managed version be ported back to pci_intx().
> > >
> > > This way we'd get this PCI API consistent again.
> > >
> > > Patch "Remove devres from pci_intx()" obviously reverts the
> > > previous
> > > patches that made drivers use pci_intx_unmanaged(). But this way
> > > it's
> > > easier to review and approve. It also makes sure that each
> > > checked out
> > > commit should provide correct behavior, not just the entire
> > > series as a
> > > whole.
> > >
> > > Merge plan for this is to enter through the PCI tree.
> > >
> > > [1]
> > > https://lore.kernel.org/all/20241009083519.10088-1-pstanner@redhat.com/
> >
> > I *think* this series depends on resolution of Takashi's "Restore
> > the
> > original INTX_DISABLE bit by pcim_intx()" patch [2], right?
>
> IIUC, it's not really dependent, as pcim_intx() has been used in
> pci_intx() internally when the PCI device is already managed.
> My patch is to correct the already existing behavior.

IOW, pcim_intx() does not behave correctly, independently from removing
the call to it in pci_intx().

>   So I guess you
> can take this series, and I'll post the revised patch later (sorry, I
> was too busy for other tasks).
>
>
> thanks,
>
> Takashi
>
> >
> > For now I'm postponing this series, but let me know if that's not
> > the
> > right thing.

There are still several reviews / acks missing from the respective
driver maintainers, so there's no hurry with this series regarding your
side ;)

Regards
P.

> >
> > [2] https://lore.kernel.org/r/20241024155539.19416-1-tiwai@suse.de
> >
> > > Philipp Stanner (13):
> > >   PCI: Prepare removing devres from pci_intx()
> > >   ALSA: hda_intel: Use always-managed version of pcim_intx()
> > >   drivers/xen: Use never-managed version of pci_intx()
> > >   net/ethernet: Use never-managed version of pci_intx()
> > >   net/ntb: Use never-managed version of pci_intx()
> > >   misc: Use never-managed version of pci_intx()
> > >   vfio/pci: Use never-managed version of pci_intx()
> > >   PCI: MSI: Use never-managed version of pci_intx()
> > >   ata: Use always-managed version of pci_intx()
> > >   wifi: qtnfmac: use always-managed version of pcim_intx()
> > >   HID: amd_sfh: Use always-managed version of pcim_intx()
> > >   Remove devres from pci_intx()
> > >   PCI: Deprecate pci_intx(), pcim_intx()
> > >
> > >  drivers/ata/ahci.c                            |  2 +-
> > >  drivers/ata/ata_piix.c                        |  2 +-
> > >  drivers/ata/pata_rdc.c                        |  2 +-
> > >  drivers/ata/sata_sil24.c                      |  2 +-
> > >  drivers/ata/sata_sis.c                        |  2 +-
> > >  drivers/ata/sata_uli.c                        |  2 +-
> > >  drivers/ata/sata_vsc.c                        |  2 +-
> > >  drivers/hid/amd-sfh-hid/amd_sfh_pcie.c        |  4 +--
> > >  drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_init.c |  2 +-
> > >  .../wireless/quantenna/qtnfmac/pcie/pcie.c    |  2 +-
> > >  drivers/pci/devres.c                          | 29 +++++--------
> > > ------
> > >  drivers/pci/pci.c                             | 19 ++++--------
> > >  include/linux/pci.h                           |  1 +
> > >  sound/pci/hda/hda_intel.c                     |  2 +-
> > >  14 files changed, 26 insertions(+), 47 deletions(-)
> > >
> > > --
> > > 2.47.0
> > >
>