From patchwork Mon May 4 17:57:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 226355 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 2C77FC4724C for ; Mon, 4 May 2020 18:12:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0500120663 for ; Mon, 4 May 2020 18:12:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615965; bh=S3qVz86W9Zi3NKQ3uIhkmOHzINLqKzJQXU7d9JYSU3w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CO5NgqhW7ysw6r2oePPrrIgG0/2GEOgE7EooyNuohcW5TBLfc5q0eN7TCOpP+Oyo2 8hudDImcrB+owkIU2N8qDBHrxV0Oz6ignlT4sU1fVxE6JjRrcsMBOs8EcW1FQMYdea ePZgxjXN5129n9wuLEVE8WNG9vpAl/r8pQrj7PRk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730814AbgEDSMo (ORCPT ); Mon, 4 May 2020 14:12:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:58402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731292AbgEDSCN (ORCPT ); Mon, 4 May 2020 14:02:13 -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 C9B52206B8; Mon, 4 May 2020 18:02:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615333; bh=S3qVz86W9Zi3NKQ3uIhkmOHzINLqKzJQXU7d9JYSU3w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JQvgeTtJsa6brAdkcs8KubWb5Vt4cbiqI6g20uEImZBjSpJ0tENiQ01cJhwVuwFa6 o5C9n7HkpiH9+LsE0V8onQimDDCGV0asMO3nWR4qbu87DzCebpez2VvrNozz/50skg Ux6uucRVQ3UlqQykMvc2M8GwKmbtaY10qsuR0QwU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Ulf Hansson Subject: [PATCH 4.19 34/37] mmc: sdhci-pci: Fix eMMC driver strength for BYT-based controllers Date: Mon, 4 May 2020 19:57:47 +0200 Message-Id: <20200504165451.689053478@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200504165448.264746645@linuxfoundation.org> References: <20200504165448.264746645@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 @@ -556,6 +556,9 @@ 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; }