From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756661Ab2K0VYE (ORCPT ); Tue, 27 Nov 2012 16:24:04 -0500 Received: from mga03.intel.com ([143.182.124.21]:6938 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753857Ab2K0VYC (ORCPT ); Tue, 27 Nov 2012 16:24:02 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,174,1355126400"; d="scan'208";a="223250660" Message-ID: <50B52F70.6080209@intel.com> Date: Tue, 27 Nov 2012 14:24:00 -0700 From: Dave Jiang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: Dan Williams CC: vinod.koul@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ioat: remove chanerr mask setting for IOAT v3.x References: <20121116232638.1766.86886.stgit@djiang5-linux.ch.intel.com> In-Reply-To: X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/26/2012 09:56 PM, Dan Williams wrote: > On Fri, Nov 16, 2012 at 3:26 PM, Dave Jiang wrote: >> The CHANERRMSK_INT register should be 0. The existing code set a value >> for a workaround to address a pre-silicon bug on the Intel 5520 IO hub that >> has been fixed when the hardware was released. There is no need for this >> code. >> >> Signed-off-by: Dave Jiang >> --- >> >> drivers/dma/ioat/dma_v3.c | 8 ++------ >> 1 file changed, 2 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c >> index f7f1dc6..60c15c4 100644 >> --- a/drivers/dma/ioat/dma_v3.c >> +++ b/drivers/dma/ioat/dma_v3.c >> @@ -1126,12 +1126,8 @@ static int ioat3_reset_hw(struct ioat_chan_common *chan) >> chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET); >> writel(chanerr, chan->reg_base + IOAT_CHANERR_OFFSET); >> >> - /* -= IOAT ver.3 workarounds =- */ >> - /* Write CHANERRMSK_INT with 3E07h to mask out the errors >> - * that can cause stability issues for IOAT ver.3, and clear any >> - * pending errors >> - */ >> - pci_write_config_dword(pdev, IOAT_PCI_CHANERRMASK_INT_OFFSET, 0x3e07); >> + /* clearn CHANERRMASK_INT and clear any pending errors */ >> + pci_write_config_dword(pdev, IOAT_PCI_CHANERRMASK_INT_OFFSET, 0); > Can we get rid of this write / register access altogether? Then the > driver will load on systems where extended pci configuration space is > not available. So this entire thing does read and write to a mask register and the error register. Were you wanting both removed? I think we may still want to clear the error register. If that's the case, it doesn't get around the extended PCI config space issue.