Re: Question on MSI support in PCI and PCI-E devices

[Stephen Hemminger]

On Wed, 11 Feb 2015 18:19:00 +0000
Andrey Utkin <andrey.krieger.utkin@xxxxxxxxx> wrote:

> Is it true that _every_ PCI or PCI Express device supporting MSI is
> indicated by some mention of MSI in "lspci -v", and if there's no such
> mention, it surely doesn't support MSI?
> 

Look at kernel source (drivers/pci/msi.c) function pci_msi_supported
there are many things which can block MSI.

There can be cases where PCI quirks in kernel block MSI
because for example the device supports MSI, but the motherboard
BIOS is broken. This only happens on really old systems.
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