RE: [PATCH] pci-hyperv: Use only 16 bit integer for PCI domain
- Date: Thu, 20 Apr 2017 18:37:35 +0000
- From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
- Subject: RE: [PATCH] pci-hyperv: Use only 16 bit integer for PCI domain
> -----Original Message-----
> From: Bjorn Helgaas [mailto:bhelgaas@xxxxxxxxxx]
> Sent: Thursday, April 20, 2017 2:33 PM
> To: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>;
> Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>; olaf@xxxxxxxxx;
> vkuznets@xxxxxxxxxx; driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; linux-
> Subject: Re: [PATCH] pci-hyperv: Use only 16 bit integer for PCI domain
> On Thu, Apr 20, 2017 at 11:35 AM, Haiyang Zhang
> <haiyangz@xxxxxxxxxxxxxxxxxxxxxx> wrote:
> > From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> > This patch uses the lower 16 bits of the serial number as PCI
> > domain, otherwise some drivers may not be able to handle it.
> Can you give any more details about this? Which drivers, for
> instance? Why do drivers care about the domain at all? Can we or
> should we make this more explicit and consistent in the PCI core,
> e.g., pci_domain_nr() is currently defined to return "int"; maybe it
> should be u32? (Although I think "int" is the same size as "u32" on
> all arches anyway).
It's Nvidia driver.
Piotr, could you explain why the driver expects 16 bit domain number?