From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46BB6C74A5B for ; Wed, 29 Mar 2023 17:05:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229760AbjC2RFV (ORCPT ); Wed, 29 Mar 2023 13:05:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229638AbjC2RFU (ORCPT ); Wed, 29 Mar 2023 13:05:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 132221FC6; Wed, 29 Mar 2023 10:05:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A291961D14; Wed, 29 Mar 2023 17:05:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA0E3C433D2; Wed, 29 Mar 2023 17:05:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680109517; bh=ItVnaZ8FUAX4pSnv5WsIqGPOgOFkxmneK6Rfun+mOtY=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=c1+JvlWVoHxfTWRdSlzBTwUTIw3f3QETPbe52cty0rY36OZA8abs67W9qizwgOuWF 5IoLpxrEH5RzrH0UDNkXIvYL0rJJ4nqbwLZvs9c1FE3l7qMRwtdK86SA1QFzXFtSTG TiLe9iNTx8he8OyIWwpiVH0BPml1o7ksCnTZEFwhbqAqexfmj4URDBKcfd1rt50Epl J90k/f6t1FaOqo+dKSXZOo07HREotWF3WjX2NQwkQ9I56eUMT0OPt0An7JdL938eB5 qXP8UeRrkkx7lE2KOWw5Rd332/3xQoJHwsUJhSWQNUPRNPSFwBV1WjL0gd5gRgkDKh LWmaY0kiJgrsA== Date: Wed, 29 Mar 2023 12:05:15 -0500 From: Bjorn Helgaas To: Wu Zongyong Cc: sdonthineni@nvidia.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, wllenyj@linux.alibaba.com, wutu.xq2@linux.alibaba.com, gerry@linux.alibaba.com Subject: Re: [RFC PATCH] PCI: avoid SBR for NVIDIA T4 Message-ID: <20230329170515.GA3067097@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <388bc353a5f88edb502ec04c0dc53ab62a526020.1680090885.git.wuzongyong@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Mar 29, 2023 at 07:58:45PM +0800, Wu Zongyong wrote: > Secondary bus reset will fail if NVIDIA T4 card is direct attached to a > root port. Blank line between paragraphs. Rewrap to fill 75 columns if it's a single paragraph. Is this only a problem when direct attached to a Root Port? Why would that be? If it's *not* related to being directly under a Root Port, don't mention that at all. > So avoid to do bus reset, pci_parent_bus_reset() works nomarlly. > > Maybe NVIDIA guys can do some detailed explanation abount the SBR > behaviour of GPUs. This is a follow-on to 4c207e7121fa ("PCI: Mark some NVIDIA GPUs to avoid bus reset"), so probably should have a Fixes: tag so it goes whereever that commit goes. Also copy the subject line from 4c207e7121fa, e.g., PCI: Mark NVIDIA T4 GPUs to avoid bus reset Are there any problem reports or bugzilla issues you can include a URL to? > Signed-off-by: Wu Zongyong > --- > drivers/pci/quirks.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 44cab813bf95..be86b93b9e38 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -3618,7 +3618,7 @@ static void quirk_no_bus_reset(struct pci_dev *dev) > */ > static void quirk_nvidia_no_bus_reset(struct pci_dev *dev) > { > - if ((dev->device & 0xffc0) == 0x2340) > + if ((dev->device & 0xffc0) == 0x2340 || dev->device == 0x1eb8) > quirk_no_bus_reset(dev); > } > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, > -- > 2.34.3 >