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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DE10ECE58F for ; Tue, 15 Oct 2019 08:16:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0318720650 for ; Tue, 15 Oct 2019 08:16:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OHDKau5y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728634AbfJOIQV (ORCPT ); Tue, 15 Oct 2019 04:16:21 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:40152 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727962AbfJOIQV (ORCPT ); Tue, 15 Oct 2019 04:16:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Z7zb8hwdUvM4gWBjniUrfCCpeZFbxnEJV1qTM/lkvII=; b=OHDKau5y8c7YAepQgJhwyx+OE 1DX8y2NcUjlALU49vt3s8qRfvOIBXlOoJDHvviOemYJWZjHFpN6gd6wHraUIlTmxiUe9c+roa67fc /ADANaqg0mE3kerF5EQlvhA2WO+oU6UNW0kEoiCSJQ0ByKsskbr79cWZXsN5/TVUcJ4e1MymZO3FV 1rnOfv4BLf5QfiirP5zYm+8gM3B8JftOBHIlj6l92646m4LpBJy2bqMHHo6cV+hYOyUPbUnT7p4UL YWYbRiVQaZwnjg9q1SP/5anlZ5lte5BkOF+bFoYR9p/SSD5U7psBI6K1Pa1gezOIzATHJOR2rxAoy J++tB0Pvw==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iKI0C-0007wo-62; Tue, 15 Oct 2019 08:16:20 +0000 Date: Tue, 15 Oct 2019 01:16:20 -0700 From: Christoph Hellwig To: Pankaj Dubey Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, bhelgaas@google.com, andrew.murray@arm.com, lorenzo.pieralisi@arm.com, gustavo.pimentel@synopsys.com, jingoohan1@gmail.com, vidyas@nvidia.com, Anvesh Salveru Subject: Re: [PATCH v3] PCI: dwc: Add support to add GEN3 related equalization quirks Message-ID: <20191015081620.GA28204@infradead.org> References: <1571108362-25962-1-git-send-email-pankaj.dubey@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1571108362-25962-1-git-send-email-pankaj.dubey@samsung.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 15, 2019 at 08:29:22AM +0530, Pankaj Dubey wrote: > From: Anvesh Salveru > > In some platforms, PCIe PHY may have issues which will prevent linkup > to happen in GEN3 or higher speed. In case equalization fails, link will > fallback to GEN1. > > DesignWare controller gives flexibility to disable GEN3 equalization > completely or only phase 2 and 3 of equalization. > > This patch enables the DesignWare driver to disable the PCIe GEN3 > equalization by enabling one of the following quirks: > - DWC_EQUALIZATION_DISABLE: To disable GEN3 equalization all phases > - DWC_EQ_PHASE_2_3_DISABLE: To disable GEN3 equalization phase 2 & 3 > > Platform drivers can set these quirks via "quirk" variable of "dw_pcie" > struct. Please submit this together with the changes to the dwc frontend driver that actually wants to set these quirks.