From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [net-next PATCH 1/2] PCI: Add PCI quirk to disable L0s ASPM state for 82575 and 82598 Date: Tue, 3 Mar 2009 21:05:26 -0700 Message-ID: <20090304040526.GB1884@parisc-linux.org> References: <20090304020308.15176.40527.stgit@lost.foo-projects.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, netdev@vger.kernel.org, gospo@redhat.com, Alexander Duyck , linux-pci , Matthew Wilcox , Jesse Barnes To: Jeff Kirsher Return-path: Content-Disposition: inline In-Reply-To: <20090304020308.15176.40527.stgit@lost.foo-projects.org> Sender: linux-pci-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Mar 03, 2009 at 06:03:09PM -0800, Jeff Kirsher wrote: > From: Alexander Duyck > > This patch is intended to disable L0s ASPM link state for 82598 (ixgbe) > parts due to the fact that it is possible to corrupt TX data when coming > back out of L0s on some systems. The workaround had been added for 82575 > (igb) previously, but did not use the ASPM api. This quirk uses the ASPM > api to prevent the ASPM subsystem from re-enabling the L0s state. > > Instead of adding the fix in igb to the ixgbe driver as well it was > decided to move it into a pci quirk. It is necessary to move the fix out > of the driver and into a pci quirk in order to prevent the issue from > occuring prior to driver load to handle the possibility of the device being > passed to a VM via direct assignment. Thanks for the explanation, it handles my immediate question of "why do it in a quirk?" It does, however, raise the very interesting question about what to do about other devices which have issues that are currently handled in the driver that can't be handled by the driver in a VM. I don't have a good example to hand right now, but I bet I can spot one when I'm less tired. > Signed-off-by: Alexander Duyck > Signed-off-by: Jeff Kirsher > CC: linux-pci > CC: Matthew Wilcox > CC: Jesse Barnes I'm not going to ack this patch at this point, let's just give it a day. FWIW, Jesse is not going to be able to review patches this week. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."