From patchwork Wed Oct 28 23:15:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajat Jain X-Patchwork-Id: 11864047 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1E56814B4 for ; Wed, 28 Oct 2020 23:16:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8E4D20759 for ; Wed, 28 Oct 2020 23:16:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Nx7qGJFA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732144AbgJ1XQW (ORCPT ); Wed, 28 Oct 2020 19:16:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390099AbgJ1XPu (ORCPT ); Wed, 28 Oct 2020 19:15:50 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8165AC0613CF for ; Wed, 28 Oct 2020 16:15:49 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id t12so645430pgv.0 for ; Wed, 28 Oct 2020 16:15:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:message-id:mime-version:subject:from:to:cc; bh=iUnZeYRK4vIboje11z8E0pGSWAL3LEqKSuUfRc5J478=; b=Nx7qGJFAN71ZNXZS3f/KvFge75PMmyvgSthe2fi9fuuLd9kBiRU+g/gxnwfOCtD7XQ cd95k9wwthMblc1KvxkKivjN7csRKnTWHMcWD0bnSjjFYPjYueviYqoNkImusTWN6iv+ UzJqLs6cL7xMjKy/ajuzP1dzmfANQ0kwv0BaAMtdhfRbysZpdZpWkqD254KzizOWsEAU kA/rLsDWEOnCdo5er+cV4yzeXeLuCcp+Cn0FnYVAT2zx8DThFhMq/aTyZBXNJF9PM0Q8 Tx8QymHd+glDouMxYxSCtuEVwOshLcYd6BINi2oqhCRdFUedHxxpEHcuKLQdvG+Dkx2/ SM/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=iUnZeYRK4vIboje11z8E0pGSWAL3LEqKSuUfRc5J478=; b=rToAS0fWlAciBrfnCGV4VimEO/gZgkyhQnj8bOPbaxFHeDswGd4CUjz3zMT11ykULW VxEetDDEP30t8Eu/Og0hNN4EdjmbafUPv7GQqf3G2jwD67oFb7nk/ayypMFUcCCADkBg UNLtWHLdiW/aAW9SYCEj1mmeoF01sTRbKDetX0eMeUy7fQ6oMK7cNkJXrOsGEQkoB0u5 fu2yQQakRNxeRgelFR8f/jt+td5OBHLdh7Q1+ToFxRX67ruSTKlRkRj0XuXCZDvKFXmS ipy5sdvfxxnhTtnkMsCXlY4x2yQEEIW3fAdqttoL47RA7wBfy91Wt+GhrsrLlbu4zLni SBsA== X-Gm-Message-State: AOAM5318yKl8M8DrP0NntObtf5i9g8Xa0ur59rOG/C8+Tin5yFAW7OKv Fo3/QI/wvNiylV/M4RivSr+GuLrXwLUy X-Google-Smtp-Source: ABdhPJyhZ1xZSKNtV7pkxJxe2Ej0Li1jfs80R9AeGKbreMvPVV7BAYH0YSmiEUDAktMxvXMu4jWO66TVxQmY Sender: "rajatja via sendgmr" X-Received: from rajat2.mtv.corp.google.com ([2620:15c:202:201:f693:9fff:fef4:3c89]) (user=rajatja job=sendgmr) by 2002:aa7:8c50:0:b029:160:1240:493d with SMTP id e16-20020aa78c500000b02901601240493dmr1287008pfd.31.1603926948983; Wed, 28 Oct 2020 16:15:48 -0700 (PDT) Date: Wed, 28 Oct 2020 16:15:45 -0700 Message-Id: <20201028231545.4116866-1-rajatja@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.29.1.341.ge80a0c044ae-goog Subject: [PATCH] PCI: Always call pci_enable_acs() regardless of pdev->acs_cap From: Rajat Jain To: 0001-PCI-Always-call-pci_enable_acs-regardless-of-pdev-ac.patch@google.com, linux-pci@vger.kernel.org, "Boris V." , Linux Kernel Mailing List , Bjorn Helgaas Cc: rajatxjain@gmail.com, Rajat Jain Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Some devices may have have anomalies with the ACS cpability structure, and they may be using quirks to support ACS functionality via other registers. For such devices, it is important we always call pci_enable_acs() to give the quirks a chance to enable ACS in other ways. For Eg: There seems a class of Intel devices quirked with *_intel_pch_acs_* functions, that do not expose the standard ACS capability structure. But these quirks help support ACS on these devices using other registers: pci_quirk_enable_intel_pch_acs() -> doesn't use acs_cap to enable ACS This has already been taken care of in the quirks, in the other direction i.e. when checking if the ACS is enabled or not. So no need to do anything there. Reported-by: Boris V Fixes: 52fbf5bdeeef ("PCI: Cache ACS capability offset in device") Signed-off-by: Rajat Jain Reviewed-by: Alex Williamson --- drivers/pci/pci.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6d4d5a2f923d..ab398226c55e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3516,8 +3516,13 @@ void pci_acs_init(struct pci_dev *dev) { dev->acs_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS); - if (dev->acs_cap) - pci_enable_acs(dev); + /* + * Attempt to enable ACS regardless of capability because some rootports + * (e.g. the ones quirked with *_intel_pch_acs_*) may not expose + * standard rootport capability structure, but still may support ACS via + * those quirks. + */ + pci_enable_acs(dev); } /**