Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756569Ab2HTWOS (ORCPT ); Mon, 20 Aug 2012 18:14:18 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:56887 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754289Ab2HTWOQ (ORCPT ); Mon, 20 Aug 2012 18:14:16 -0400 MIME-Version: 1.0 In-Reply-To: References: <1343836477-7287-1-git-send-email-jiang.liu@huawei.com> <50325732.3000700@gmail.com> <50325C18.9030207@gmail.com> From: Bjorn Helgaas Date: Mon, 20 Aug 2012 16:13:54 -0600 Message-ID: Subject: Re: [PATCH v3 00/32] provide interfaces to access PCIe capabilities registers To: Jiang Liu , Yu Zhao , Dexuan Cui Cc: Don Dutile , Yinghai Lu , Taku Izumi , "Rafael J . Wysocki" , Kenji Kaneshige , Yijing Wang , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1970 Lines: 42 On Mon, Aug 20, 2012 at 10:10 AM, Bjorn Helgaas wrote: > So I'll try pulling your branch (I'll do something about the tsi721.c > stuff myself). I pulled this into git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git pci/jiang-pcie-cap with the following changes: - Dropped some "pci_" prefixes on internal functions in access.c - Minor restructure of pcie_capability_read_*() - Removed export of pcie_capability_reg_implemented() - Reworked reset_intel_82599_sfp_virtfn() to check for FLR bit in DEVCAP rather than using pcie_capability_reg_implemented() - Split driver patches into one driver per patch - Fixed myri10ge_toggle_relaxed() -- previous code returned useful value, but your patch made it always return zero - Use 16-bit, not 32-bit, accesses for DEVCTL, DEVCTL2 (tsi721) I am still concerned about reset_intel_82599_sfp_virtfn(). It looks wrong and possibly unnecessary. It looks wrong because it sets PCI_EXP_DEVCTL_BCR_FLR and blindly clears all other bits in PCI_EXP_DEVCTL. Most of the bits are probably cleared by the FLR anyway, but Aux Power PM Enable is RWS ("sticky"), so it is *not* modified by FLR. Therefore, using reset_intel_82599_sfp_virtfn() has the probably unintended side effect of clearing Aux Power PM Enable. It looks possibly unnecessary because the generic pcie_flr() does essentially the same thing, so it's not clear why we need a special case for 82599. Yu or Dexuan, can you comment on these 82599 questions? The proposed new code is here: http://git.kernel.org/?p=linux/kernel/git/helgaas/pci.git;a=blob;f=drivers/pci/quirks.c;h=9abbf56e93fe5c98364a7dfe2b0b724047dfa4a9;hb=ef529bf0cb5606ff5bd1422d2d2700a821d8218b#l3082 Bjorn -- 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/