From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Alexander Stein To: Tomoya MORINAGA Cc: Chris Ball , Jesse Barnes , Adrian Hunter , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH 3/3] mmc: sdhci-pci: allow 8-bit bus width for Intel PCH Date: Wed, 14 Mar 2012 08:26:07 +0100 Message-ID: <2073158.vCQHRDAdga@ws-stein> In-Reply-To: References: <1331659002-13743-1-git-send-email-alexander.stein@systec-electronic.com> <1331659002-13743-3-git-send-email-alexander.stein@systec-electronic.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: Hello Tomoya, Am Mittwoch, 14. März 2012, 10:17:35 schrieb Tomoya MORINAGA: > Hi Alexander > > As a matter of interest, > do you mean that current MMC of eg20t on Linux doesn't support 8-bit access? We have a board with an 8-bit connected eMMC and Linux only used 4-bit wide bus access. After some research IMO the device is only matched to the default PCI id class > PCI_DEVICE_CLASS((PCI_CLASS_SYSTEM_SDHCI << 8), 0xFFFF00) AFAICS it's the same issue with the Medfield eMMC where 8-bit bus support is added in 0d013bcf5c272faea1f8e7a5ef3cb2e98103d5cb This also states the default is 4-bit bus width which I saw before. Regards, Alexander -- Dipl.-Inf. Alexander Stein SYS TEC electronic GmbH August-Bebel-Str. 29 D-07973 Greiz Tel: +49-3661-6279-0, Fax: +49-3661-6279-99 eMail: Alexander.Stein@systec-electronic.com Internet: http://www.systec-electronic.com Managing Director: Dipl.-Phys. Siegmar Schmidt Commercial registry: Amtsgericht Jena, HRB 205563