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Message-ID: <105f167697e4421237884ebece1cf9a28293c762.camel@redhat.com>
Subject: Re: [PATCH v7 09/13] PCI: Give pcim_set_mwi() its own devres
 callback
From: Philipp Stanner <pstanner@redhat.com>
To: Ilpo =?ISO-8859-1?Q?J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>, Maarten Lankhorst
 <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
 Thomas Zimmermann <tzimmermann@suse.de>, David Airlie <airlied@gmail.com>,
 Daniel Vetter <daniel@ffwll.ch>, Bjorn Helgaas <bhelgaas@google.com>, Sam
 Ravnborg <sam@ravnborg.org>, dakr@redhat.com, 
 dri-devel@lists.freedesktop.org, LKML <linux-kernel@vger.kernel.org>, 
 linux-pci@vger.kernel.org
Date: Fri, 14 Jun 2024 10:15:22 +0200
In-Reply-To: <17445053-18a1-a56d-79d0-3b3d3ecab033@linux.intel.com>
References: <20240605081605.18769-2-pstanner@redhat.com>
	 <20240605081605.18769-11-pstanner@redhat.com>
	 <17445053-18a1-a56d-79d0-3b3d3ecab033@linux.intel.com>
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On Thu, 2024-06-13 at 20:19 +0300, Ilpo J=C3=A4rvinen wrote:
> On Wed, 5 Jun 2024, Philipp Stanner wrote:
>=20
> > Managing pci_set_mwi() with devres can easily be done with its own
> > callback, without the necessity to store any state about it in a
> > device-related struct.
> >=20
> > Remove the MWI state from struct pci_devres.
> > Give pcim_set_mwi() a separate devres-callback.
> >=20
> > Signed-off-by: Philipp Stanner <pstanner@redhat.com>
> > ---
> > =C2=A0drivers/pci/devres.c | 29 ++++++++++++++++++-----------
> > =C2=A0drivers/pci/pci.h=C2=A0=C2=A0=C2=A0 |=C2=A0 1 -
> > =C2=A02 files changed, 18 insertions(+), 12 deletions(-)
> >=20
> > diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
> > index 936369face4b..0bafb67e1886 100644
> > --- a/drivers/pci/devres.c
> > +++ b/drivers/pci/devres.c
> > @@ -361,24 +361,34 @@ void __iomem
> > *devm_pci_remap_cfg_resource(struct device *dev,
> > =C2=A0}
> > =C2=A0EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
> > =C2=A0
> > +static void __pcim_clear_mwi(void *pdev_raw)
> > +{
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0struct pci_dev *pdev =3D pde=
v_raw;
> > +
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0pci_clear_mwi(pdev);
> > +}
> > +
> > =C2=A0/**
> > =C2=A0 * pcim_set_mwi - a device-managed pci_set_mwi()
> > - * @dev: the PCI device for which MWI is enabled
> > + * @pdev: the PCI device for which MWI is enabled
> > =C2=A0 *
> > =C2=A0 * Managed pci_set_mwi().
> > =C2=A0 *
> > =C2=A0 * RETURNS: An appropriate -ERRNO error value on error, or zero
> > for success.
> > =C2=A0 */
> > -int pcim_set_mwi(struct pci_dev *dev)
> > +int pcim_set_mwi(struct pci_dev *pdev)
> > =C2=A0{
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0struct pci_devres *dr;
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0int ret;
> > =C2=A0
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0dr =3D find_pci_dr(dev);
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0if (!dr)
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0return -ENOMEM;
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0ret =3D devm_add_action(&pde=
v->dev, __pcim_clear_mwi, pdev);
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0if (ret !=3D 0)
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0return ret;
> > +
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0ret =3D pci_set_mwi(pdev);
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0if (ret !=3D 0)
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0devm_remove_action(&pdev->dev, __pcim_clear_mwi,
> > pdev);
>=20
> I'm sorry if this is a stupid question but why this cannot use=20
> devm_add_action_or_reset()?

For MWI that could be done.

This is basically just consistent with the new pcim_enable_device() in
patch No.11 where devm_add_action_or_reset() could collide with
pcim_pin_device().

We could squash usage of devm_add_action_or_reset() in here. I don't
care.

P.


>=20
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0dr->mwi =3D 1;
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0return pci_set_mwi(dev);
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0return ret;
> > =C2=A0}
> > =C2=A0EXPORT_SYMBOL(pcim_set_mwi);
>=20