From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932417Ab1LOJd0 (ORCPT ); Thu, 15 Dec 2011 04:33:26 -0500 Received: from metis.ext.pengutronix.de ([92.198.50.35]:37553 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752934Ab1LOJdZ (ORCPT ); Thu, 15 Dec 2011 04:33:25 -0500 Date: Thu, 15 Dec 2011 10:33:19 +0100 From: Sascha Hauer To: Dong Aisheng-B29396 Cc: Linus Walleij , Guo Shawn-R65073 , "linus.walleij@stericsson.com" , "linux-kernel@vger.kernel.org" , "rob.herring@calxeda.com" , "grant.likely@secretlab.ca" , "linux-arm-kernel@lists.infradead.org" , "kernel@pengutronix.de" Subject: Re: [RFC PATCH v2 4/4] mmc: sdhci-esdhc-imx: using pinmux subsystem Message-ID: <20111215093319.GO27267@pengutronix.de> References: <1323878622-26602-1-git-send-email-b29396@freescale.com> <1323878622-26602-5-git-send-email-b29396@freescale.com> <20111214211152.GM27267@pengutronix.de> <20111215070505.GA22541@S2101-09.ap.freescale.net> <7FE21149F4667147B645348EC60578850564C5@039-SN2MPN1-013.039d.mgd.msft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7FE21149F4667147B645348EC60578850564C5@039-SN2MPN1-013.039d.mgd.msft.net> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 10:32:41 up 32 days, 17:19, 47 users, load average: 0.09, 0.10, 0.44 User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:6f8:1178:2:21e:67ff:fe11:9c5c X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 15, 2011 at 08:59:28AM +0000, Dong Aisheng-B29396 wrote: > > -----Original Message----- > > From: Linus Walleij [mailto:linus.walleij@linaro.org] > > Sent: Thursday, December 15, 2011 4:27 PM > > To: Guo Shawn-R65073 > > Cc: Sascha Hauer; Dong Aisheng-B29396; linus.walleij@stericsson.com; > > linux-kernel@vger.kernel.org; rob.herring@calxeda.com; > > grant.likely@secretlab.ca; linux-arm-kernel@lists.infradead.org; > > kernel@pengutronix.de > > Subject: Re: [RFC PATCH v2 4/4] mmc: sdhci-esdhc-imx: using pinmux > > subsystem > > Importance: High > > > > On Thu, Dec 15, 2011 at 8:05 AM, Shawn Guo > > wrote: > > >[Me] > > >> So if you want to do this for i.MX you need something like selectable > > >> dummy pinmuxes, i.e. pinmux_get() to return something that just say > > >> "OK" to everything like the dummy regulators. > > >> > > >> Shall I try to create something like that? > > >> > > > Isn't the empty functions defined in include/linux/pinctrl/pinmux.h > > > for this purpose? > > > > No, these are for compiling it *out*, dummy pinmuxes would be if you > > compile it *in*, but don't find an apropriate pinmux, you still get > > something that does nothing and still works. > > > > Dummy regulators work exactly this way. > > > > I did not read the dummy regulator code too much. > But does it mean that the dummy regulator or dummy pinmux will also hide the > Real errors since it will always get a available one? > How do we distinguish between the two case(real error and fake error)? We don't :( That's the problem with the dummy regulator. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |