From patchwork Mon May 4 17:57:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226408 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 04381C3A5A9 for ; Mon, 4 May 2020 18:05:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D39842073E for ; Mon, 4 May 2020 18:05:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615533; bh=e6ccMfhxtpK7sTocC+QkoGt/nt9t13JWpEXbmbDlFks=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R7GcqwpaJ4uLdb9DAM4m2o8f7xMQuIBqNou6IZLry0x8VtS+CRw9lgrHSD0utm2V7 bhXq9xmzto4toOWpWqZjkJi1Q+Qa0VBvAARIqF2HPpza5NWfviXHMUa6bLiH+YjEhr 65RSxtb7k1ewj7QRpXev4bmk2pLNBXBerTM7w3/A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731240AbgEDSFb (ORCPT ); Mon, 4 May 2020 14:05:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:35326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731828AbgEDSF3 (ORCPT ); Mon, 4 May 2020 14:05:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5B9E32073B; Mon, 4 May 2020 18:05:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615528; bh=e6ccMfhxtpK7sTocC+QkoGt/nt9t13JWpEXbmbDlFks=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iGn8zbbQPuPompI2z1VhB6esQZB1bBMRIEJQkSy2gspx3Cq8z9Bpo7Sr2rcr2ScyH Z1wBD3sY5R1fm8/stRr77cN7VZLF2pO8le9NhYN6OSyhrcbIIwbe/d2PCwsfI3ITU1 RQbRRSHE3D9Oxr619aUchPfTw+RPcX2t9i7ggpdA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Ulf Hansson Subject: [PATCH 5.6 18/73] mmc: sdhci-pci: Fix eMMC driver strength for BYT-based controllers Date: Mon, 4 May 2020 19:57:21 +0200 Message-Id: <20200504165505.189933665@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200504165501.781878940@linuxfoundation.org> References: <20200504165501.781878940@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Adrian Hunter commit 1a8eb6b373c2af6533c13d1ea11f504e5010ed9a upstream. BIOS writers have begun the practice of setting 40 ohm eMMC driver strength even though the eMMC may not support it, on the assumption that the kernel will validate the value against the eMMC (Extended CSD DRIVER_STRENGTH [offset 197]) and revert to the default 50 ohm value if 40 ohm is invalid. This is done to avoid changing the value for different boards. Putting aside the merits of this approach, it is clear the eMMC's mask of supported driver strengths is more reliable than the value provided by BIOS. Add validation accordingly. Signed-off-by: Adrian Hunter Fixes: 51ced59cc02e ("mmc: sdhci-pci: Use ACPI DSM to get driver strength for some Intel devices") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200422111629.4899-1-adrian.hunter@intel.com Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/sdhci-pci-core.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -601,6 +601,9 @@ static int intel_select_drive_strength(s struct sdhci_pci_slot *slot = sdhci_priv(host); struct intel_host *intel_host = sdhci_pci_priv(slot); + if (!(mmc_driver_type_mask(intel_host->drv_strength) & card_drv)) + return 0; + return intel_host->drv_strength; }