Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752066AbWJNElt (ORCPT ); Sat, 14 Oct 2006 00:41:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752065AbWJNEls (ORCPT ); Sat, 14 Oct 2006 00:41:48 -0400 Received: from smtp.osdl.org ([65.172.181.4]:54717 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1752062AbWJNElr (ORCPT ); Sat, 14 Oct 2006 00:41:47 -0400 Date: Fri, 13 Oct 2006 21:41:35 -0700 From: Andrew Morton To: Matthew Wilcox Cc: Val Henson , Greg Kroah-Hartman , netdev@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] [PCI] Check that MWI bit really did get set Message-Id: <20061013214135.8fbc9f04.akpm@osdl.org> In-Reply-To: <1160161519800-git-send-email-matthew@wil.cx> References: <1160161519800-git-send-email-matthew@wil.cx> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1725 Lines: 51 On Fri, 06 Oct 2006 13:05:18 -0600 Matthew Wilcox wrote: > Since some devices may not implement the MWI bit, we should check that > the write did set it and return an error if it didn't. > > Signed-off-by: Matthew Wilcox > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index a544997..3d041f4 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -900,13 +900,17 @@ #endif > return rc; > > pci_read_config_word(dev, PCI_COMMAND, &cmd); > - if (! (cmd & PCI_COMMAND_INVALIDATE)) { > - pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev)); > - cmd |= PCI_COMMAND_INVALIDATE; > - pci_write_config_word(dev, PCI_COMMAND, cmd); > - } > - > - return 0; > + if (cmd & PCI_COMMAND_INVALIDATE) > + return 0; > + > + pr_debug("PCI: Enabling Mem-Wr-Inval for device %s\n", pci_name(dev)); > + cmd |= PCI_COMMAND_INVALIDATE; > + pci_write_config_word(dev, PCI_COMMAND, cmd); > + > + /* read result from hardware (in case bit refused to enable) */ > + pci_read_config_word(dev, PCI_COMMAND, &cmd); > + > + return (cmd & PCI_COMMAND_INVALIDATE) ? 0 : -EINVAL; > } > > /** Bisection shows that this patch (pci-check-that-mwi-bit-really-did-get-set.patch in Greg's PCI tree) breaks suspend-to-disk on my Vaio. It writes the suspend image and gets to the point where it's supposed to power down, but doesn't. After a manual power-cycle it successfully resumes from disk, but networking (at least) is dead. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/