From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932378AbaCDUWD (ORCPT ); Tue, 4 Mar 2014 15:22:03 -0500 Received: from mxout2.netvision.net.il ([194.90.9.21]:43577 "EHLO mxout2.netvision.net.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755250AbaCDUV7 (ORCPT ); Tue, 4 Mar 2014 15:21:59 -0500 X-Greylist: delayed 901 seconds by postgrey-1.27 at vger.kernel.org; Tue, 04 Mar 2014 15:21:59 EST MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset=UTF-8; format=flowed Message-id: <53163247.8000904@gmail.com> Date: Tue, 04 Mar 2014 22:06:31 +0200 From: Eli Billauer User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12) Gecko/20100907 Fedora/3.0.7-1.fc12 Thunderbird/3.0.7 To: =?UTF-8?B?U8O2cmVuIEJyaW5rbWFubg==?= Cc: chris@printf.net, michal.simek@xilinx.com, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Looijmans Subject: Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection References: <1393759200-22819-1-git-send-email-eli.billauer@gmail.com> <74003aec-1707-4f43-b947-df148d573fa1@TX2EHSMHS038.ehs.local> In-reply-to: <74003aec-1707-4f43-b947-df148d573fa1@TX2EHSMHS038.ehs.local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Sören, wp-inverted solves the practical problem indeed, and fools the driver into thinking that the card has an inverted write protection sensor, and the logic zero that it finds in the hardware register means that the card isn't write protected. I'm insisting on this patch, because I think that the device tree should describe the hardware as it is, and not fool the driver into behaving the way we want it to. These tricks always bite back later on. Regards, Eli On 04/03/14 21:26, Sören Brinkmann wrote: > Hi Eli, > > On Sun, 2014-03-02 at 01:20PM +0200, Eli Billauer wrote: > >> The write protection signal is absent on a board based upon Xilinx' Zynq >> processor ("ZyBo"). This leads the kernel to think that the MicroSD card is >> write protected, and causes a kernel panic during boot, as root fails to >> mount RW. >> > I talked to some people here at Xilinx. According to them, you have the > option to pin out the WP signal, which would mean the board needs to > tie/connect the signal properly. Or, if you select to not pin out the WP > signal, it should be tied to 0 within the chip. > Currently, I have some doubts that is the case, since Mike reported the > same issue, but would you mind double checking? > In theory the signal should default to logic zero which would at most > require to add the, already existing, 'wp-inverted' quirk when using > micro-sd on Zynq. > > Thanks, > Sören > > > >