From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga02-in.huawei.com ([119.145.14.65]:21732 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753579Ab3JJMdE (ORCPT ); Thu, 10 Oct 2013 08:33:04 -0400 Message-ID: <52569E5F.90307@huawei.com> Date: Thu, 10 Oct 2013 20:32:31 +0800 From: Yijing Wang MIME-Version: 1.0 To: Ben Hutchings CC: Bjorn Helgaas , , "Hanjun Guo" Subject: Re: [PATCH] PCI: Avoid initialize MSI/MSIX if device power state != PCI_D0 References: <1381393916-12268-1-git-send-email-wangyijing@huawei.com> <1381407317.2788.102.camel@deadeye.wl.decadent.org.uk> In-Reply-To: <1381407317.2788.102.camel@deadeye.wl.decadent.org.uk> Content-Type: text/plain; charset="UTF-8" Sender: linux-pci-owner@vger.kernel.org List-ID: On 2013/10/10 20:15, Ben Hutchings wrote: > On Thu, 2013-10-10 at 16:31 +0800, Yijing Wang wrote: >> Currently, if device power state != PCI_D0, we still initialize >> device MSI/MSIX, but we won't write the MSI message to device >> MSI/MSIX registers. It's weird, we don't configure MSI/MSIX >> registers properly, but pci_enable_msi() or pci_enable_msix() >> return success, and even these registers will never be updated later. >> So I think it should return error if device power state != PCI_D0. >> >> Signed-off-by: Yijing Wang >> --- >> drivers/pci/msi.c | 10 ++++------ >> 1 files changed, 4 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >> index d5f90d6..eb502f6 100644 >> --- a/drivers/pci/msi.c >> +++ b/drivers/pci/msi.c >> @@ -308,9 +308,7 @@ void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) >> >> void __write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) >> { >> - if (entry->dev->current_state != PCI_D0) { >> - /* Don't touch the hardware now */ >> - } else if (entry->msi_attrib.is_msix) { >> + if (entry->msi_attrib.is_msix) { > [...] > > As I said before, this function was being called to change IRQ > affinities during suspend/resume at a point when most PCI devices were > in D3. If that is no longer the case then this change is probably OK. > Otherwise you should not touch this function. Hi ben, sorry for the mistake, now I know what you worry about. I will update this patch, keep __write_msi_msg() function not changed. Only add some guard for pci_enable_msi()/pci_enable_msix() .. Thanks! Yijing. > > Ben. > -- Thanks! Yijing