Re: [PATCH 1/1] PCI: hv: Remove unused field pci_bus in struct hv_pcibus_device

["Srivatsa S. Bhat" <srivatsa@csail.mit.edu>]

On Mon, Jan 12, 2026 at 03:54:51PM +0000, Michael Kelley wrote:
> From: Srivatsa S. Bhat <srivatsa@csail.mit.edu> Sent: Monday, January 12, 2026 6:29 AM
> > Hi Michael,
> > 
> > On Sun, Jan 11, 2026 at 09:00:34AM -0800, mhkelley58@gmail.com wrote:
> > > From: Michael Kelley <mhklinux@outlook.com>
> > >
> > > Field pci_bus in struct hv_pcibus_device is unused since
> > > commit 418cb6c8e051 ("PCI: hv: Generify PCI probing"). Remove it.
> > >
> > 
> > Since that commit is several years old (2021), I was curious if this was found by
> > manual inspection or if the compiler was able to flag the unused
> > variable as well.
> 
> Code inspection. I was brushing up on how the structs defined
> in pci-hyperv.c relate to the standard Linux PCI struct pci_bus and
> struct pci_dev. Having a pointer to struct pci_bus in struct
> hv_pcibus_device makes sense, and I was a bit surprised to find
> it's not set or used. Instead, the PCI bus is always found through
> the PCI bridge.
> 

Ah, I see, thank you for the background!

Regards,
Srivatsa

> 
> > 
> > > No functional change.
> > >
> > > Signed-off-by: Michael Kelley <mhklinux@outlook.com>
> > 
> > Reviewed-by: Srivatsa S. Bhat (Microsoft) <srivatsa@csail.mit.edu>
> > 
> > Regards,
> > Srivatsa
> > Microsoft Linux Systems Group
> > 
> > > ---
> > >  drivers/pci/controller/pci-hyperv.c | 1 -
> > >  1 file changed, 1 deletion(-)
> > >
> > > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> > > index 1e237d3538f9..7fcba05cec30 100644
> > > --- a/drivers/pci/controller/pci-hyperv.c
> > > +++ b/drivers/pci/controller/pci-hyperv.c
> > > @@ -501,7 +501,6 @@ struct hv_pcibus_device {
> > >  	struct resource *low_mmio_res;
> > >  	struct resource *high_mmio_res;
> > >  	struct completion *survey_event;
> > > -	struct pci_bus *pci_bus;
> > >  	spinlock_t config_lock;	/* Avoid two threads writing index page */
> > >  	spinlock_t device_list_lock;	/* Protect lists below */
> > >  	void __iomem *cfg_addr;
> > > --
> > > 2.25.1
> > >
> > >