Re: [PATCH] PCI: vmd: override irq_startup()/irq_shutdown() in vmd_init_dev_msi_info()

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Gene, Todd, Oliver]

On Tue, Oct 14, 2025 at 04:18:24PM -0500, Bjorn Helgaas wrote:
> On Tue, Oct 14, 2025 at 09:46:07AM +0800, Inochi Amaoto wrote:
> > Since commit 54f45a30c0d0 ("PCI/MSI: Add startup/shutdown for per
> > device domains") set callback irq_startup() and irq_shutdown() of
> > the struct pci_msi[x]_template, __irq_startup() will always invokes
> > irq_startup() callback instead of irq_enable() callback overridden
> > in vmd_init_dev_msi_info(). This will not start the irq correctly.
> > 
> > Also override irq_startup()/irq_shutdown() in vmd_init_dev_msi_info(),
> > so the irq_startup() can invoke the real logic.
> > 
> > Fixes: 54f45a30c0d0 ("PCI/MSI: Add startup/shutdown for per device domains")
> > Reported-by: Kenneth Crudup <kenny@panix.com>
> > Closes: https://lore.kernel.org/all/8a923590-5b3a-406f-a324-7bd1cf894d8f@panix.com/
> > Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
> > Tested-by: Kenneth R. Crudup <kenny@panix.com>
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> 
> Thomas, I'm happy to take this via PCI you prefer.  I acked it
> because you merged 54f45a30c0d0.
> 
> If you take it, I wouldn't mind if you capitalized "Override" in the
> subject to match the history.
> 
> Obviously this is v6.18 material since 54f45a30c0d0 is a v6.18-rc1
> regression.

Not having heard anything, I put this on pci/for-linus and plan to
request a merge before -rc2.  Let me know if you plan to merge this
elsewhere and I can drop it from the PCI tree.

I added more reports to the commit log:

  PCI: vmd: Override irq_startup()/irq_shutdown() in vmd_init_dev_msi_info()

  Since commit 54f45a30c0d0 ("PCI/MSI: Add startup/shutdown for per
  device domains") set callback irq_startup() and irq_shutdown() of
  the struct pci_msi[x]_template, __irq_startup() will always invokes
  irq_startup() callback instead of irq_enable() callback overridden
  in vmd_init_dev_msi_info(). This will not start the IRQ correctly.

  Also override irq_startup()/irq_shutdown() in vmd_init_dev_msi_info(),
  so the irq_startup() can invoke the real logic.

  Fixes: 54f45a30c0d0 ("PCI/MSI: Add startup/shutdown for per device domains")
  Reported-by: Kenneth Crudup <kenny@panix.com>
  Closes: https://lore.kernel.org/r/8a923590-5b3a-406f-a324-7bd1cf894d8f@panix.com/
  Reported-by: Genes Lists <lists@sapience.com>
  Closes: https://lore.kernel.org/r/4b392af8847cc19720ffcd53865f60ab3edc56b3.camel@sapience.com
  Reported-by: Todd Brandt <todd.e.brandt@intel.com>
  Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220658
  Reported-by: Oliver Hartkopp <socketcan@hartkopp.net>
  Closes: https://lore.kernel.org/r/8d6887a5-60bc-423c-8f7a-87b4ab739f6a@hartkopp.net
  Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Tested-by: Kenneth R. Crudup <kenny@panix.com>
  Tested-by: Genes Lists <lists@sapience.com>
  Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
  Link: https://patch.msgid.link/20251014014607.612586-1-inochiama@gmail.com

> > ---
> >  drivers/pci/controller/vmd.c | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> > index 1bd5bf4a6097..b4b62b9ccc45 100644
> > --- a/drivers/pci/controller/vmd.c
> > +++ b/drivers/pci/controller/vmd.c
> > @@ -192,6 +192,12 @@ static void vmd_pci_msi_enable(struct irq_data *data)
> >  	data->chip->irq_unmask(data);
> >  }
> > 
> > +static unsigned int vmd_pci_msi_startup(struct irq_data *data)
> > +{
> > +	vmd_pci_msi_enable(data);
> > +	return 0;
> > +}
> > +
> >  static void vmd_irq_disable(struct irq_data *data)
> >  {
> >  	struct vmd_irq *vmdirq = data->chip_data;
> > @@ -210,6 +216,11 @@ static void vmd_pci_msi_disable(struct irq_data *data)
> >  	vmd_irq_disable(data->parent_data);
> >  }
> > 
> > +static void vmd_pci_msi_shutdown(struct irq_data *data)
> > +{
> > +	vmd_pci_msi_disable(data);
> > +}
> > +
> >  static struct irq_chip vmd_msi_controller = {
> >  	.name			= "VMD-MSI",
> >  	.irq_compose_msi_msg	= vmd_compose_msi_msg,
> > @@ -309,6 +320,8 @@ static bool vmd_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
> >  	if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))
> >  		return false;
> > 
> > +	info->chip->irq_startup		= vmd_pci_msi_startup;
> > +	info->chip->irq_shutdown	= vmd_pci_msi_shutdown;
> >  	info->chip->irq_enable		= vmd_pci_msi_enable;
> >  	info->chip->irq_disable		= vmd_pci_msi_disable;
> >  	return true;
> > --
> > 2.51.0
> >