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From: Stephen Hemminger <stephen@networkplumber.org>
To: Andrey Utkin <andrey.krieger.utkin@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	kernelnewbies <kernelnewbies@kernelnewbies.org>,
	"kernel-mentors@selenic.com" <kernel-mentors@selenic.com>
Subject: Re: Question on MSI support in PCI and PCI-E devices
Date: Thu, 12 Feb 2015 06:48:55 -0800	[thread overview]
Message-ID: <20150212064855.5d7ac655@uryu.home.lan> (raw)
In-Reply-To: <f236217608b24a5e976628fe31d41a03@BRMWP-EXMB11.corp.brocade.com>

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

       reply	other threads:[~2015-02-12 14:49 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <f236217608b24a5e976628fe31d41a03@BRMWP-EXMB11.corp.brocade.com>
2015-02-12 14:48 ` Stephen Hemminger [this message]
2015-02-12 15:11   ` Andrey Utkin
2015-03-02 14:02     ` McKay, Luke
2015-03-03 14:29       ` Andrey Utkin
2015-03-04 16:03         ` McKay, Luke
2015-03-04 16:30           ` Roger Heflin
2015-03-04 17:04             ` McKay, Luke
2015-03-04 17:18               ` Roger Heflin
2015-02-11 18:19 Andrey Utkin

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