Date: Mon, 14 Feb 2005 15:00:43 -0500
From: Jeff Garzik <jgarzik@pobox.com>
To: Roland Dreier <roland@topspin.com>
Cc: Greg KH <greg@kroah.com>, Linux Kernel <linux-kernel@vger.kernel.org>,
       Andrew Morton <akpm@osdl.org>, Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: avoiding pci_disable_device()...
Message-ID: <20050214200043.GA15868@havoc.gtf.org>
References: <4210021F.7060401@pobox.com> <20050214190619.GA9241@kroah.com> <4211013E.6@pobox.com> <52hdke29sh.fsf@topspin.com>
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On Mon, Feb 14, 2005 at 11:58:38AM -0800, Roland Dreier wrote:
>     Jeff> * pci_request_regions() should be axiomatic.  By that I mean,
>     Jeff> pci_enable_device() should
>     Jeff> 	(a) handle pci_request_regions() completely
>     Jeff> 	(b) fail if regions are not available
> 
> There's one pitfall here: for a device using MSI-X, the MSI-X table is
> going to be somewhere in one of the device's BARs.  When the device
> driver does pci_enable_msix(), drivers/pci/msi.c will do
> request_region() on this table.  If the device driver has already done
> pci_request_regions(), then this will fail and the driver won't be
> able to use MSI-X.  The current solution is for the driver to avoid
> requesting the whole BAR where the MSI-X table is.


That's an MSI bug.

A current PCI driver -should- be using pci_request_regions().

	Jeff


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