From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH 1/2] [PCI] Check that MWI bit really did get set Date: Fri, 06 Oct 2006 13:05:18 -0600 Message-ID: <1160161519800-git-send-email-matthew@wil.cx> Reply-To: Matthew Wilcox Cc: netdev@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org, Matthew Wilcox Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:19405 "EHLO mail.parisc-linux.org") by vger.kernel.org with ESMTP id S1422876AbWJFTFU (ORCPT ); Fri, 6 Oct 2006 15:05:20 -0400 To: Val Henson , Greg Kroah-Hartman Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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; } /**