From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: [PATCH] mmc: omap_hsmmc: Add support for Erratum 2.1.1.128 in device tree boot Date: Tue, 21 Jan 2014 11:38:00 -0600 Message-ID: <52DEB078.5030005@ti.com> References: <1390260542-22213-1-git-send-email-nm@ti.com> <20140120233941.GG6516@saruman.home> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140120233941.GG6516@saruman.home> Sender: linux-mmc-owner@vger.kernel.org To: balbi@ti.com Cc: Balaji T K , Chris Ball , Tony Lindgren , devicetree@vger.kernel.org, linux-mmc@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org On 01/20/2014 05:39 PM, Felipe Balbi wrote: > On Mon, Jan 20, 2014 at 05:29:02PM -0600, Nishanth Menon wrote: >> When device is booted using devicetree, platforms impacted by >> Erratum 2.1.1.128 is not detected easily in the mmc driver. This erratum >> indicates that the module cannot do multi-block transfers. >> >> Handle this by providing a boolean flag to indicate to driver that it is >> working on a hardware with mentioned limitation. > > sure there's no way of reading the revision register to figure this one > out without having to add a new DT attribute ? > I did a quick patch to read the Module revision register: http://slexy.org/view/s21TKvlWlR sdp2430: Revision: 1.2, Spec: 0.0, normal interrupt OMAP3430-ldp: (ES2.1): Revision: 2.6, Spec: 0.0, normal interrupt SDP3430:(ES3.0) Revision: 2.6, Spec: 0.0, normal interrupt AM3517-evm: (ES1.1): Revision: 2.6, Spec: 0.0, normal interrupt AM3517-crane:(ES1.1): Revision: 2.6, Spec: 0.0, normal interrupt AM37x-evm: (ES1.2) Revision: 2.6, Spec: 0.0, normal interrupt OMAP3630-beag-xm (ES1.2): Revision: 2.6, Spec: 0.0, normal interrupt am335x-evm:(ES1.0): Revision: 3.1, Spec: 0.1, normal interrupt am335x-sk: (ES2.1): Revision: 3.1, Spec: 0.1, normal interrupt am335x-beaglebone-black:(ES2.0): Revision: 3.1, Spec: 0.1, normal interrupt sdp4430.txt: (ES2.2): Revision: 3.1, Spec: 0.1, normal interrupt OMAP4460-panda-es (ES1.1): Revision: 3.1, Spec: 0.1, normal interrupt OMAP5uevm:(ES2.0): Revision: 3.3, Spec: 0.2, normal interrupt dra7-evm (es1.1): Revision: 3.3, Spec: 0.2, normal interrupt OMAP3430-ldp seems to be the only one impacted with module revision 2.6 -> so using revision information is not really helpful here. Hence the usage of a flag in dt attribute to indicate hardware impacted by erratum. -- Regards, Nishanth Menon