From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Wahren Subject: Re: [PATCH RFC 1/3] DT: bindings: mmc: Add property for 3.3V only support Date: Wed, 10 Aug 2016 22:27:04 +0200 (CEST) Message-ID: <853617027.179290.63a6f478-ad48-40c8-82ca-760dd1afc040.open-xchange@email.1und1.de> References: <1470488140-10104-1-git-send-email-stefan.wahren@i2se.com> <1470488140-10104-2-git-send-email-stefan.wahren@i2se.com> <20160810184451.GA13473@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160810184451.GA13473@rob-hp-laptop> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Sascha Hauer , Otavio Salvador , Holger Schurig , Shawn Guo , Dong Aisheng , linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Rutland , Ulf Hansson , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Marek Vasut , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Fabio Estevam List-Id: devicetree@vger.kernel.org Hi, > Rob Herring hat am 10. August 2016 um 20:44 geschrieben: > > > On Sat, Aug 06, 2016 at 12:55:38PM +0000, Stefan Wahren wrote: > > Currently there is no proper way to define that a MMC host supports > > only 3.3V. The property no-1-8-v is broken and has different meanings > > for different sdhci variants. So add a new property for 3.3V only > > support and mark no-1-8-v as deprecated. > > Why is it broken? i want to quote Ulf Hansson here [1]: The problem with the "no-1-8-v" binding is that it's describing what the hardware *can't* do. It thus becomes easy to abuse it. I suggest we stop using it, we should mark it deprecated. [1] - http://www.spinics.net/lists/linux-mmc/msg34604.html > How would I override a controller saying 1.8V is > supported and it is not? Sorry, i'm not sure that i understand your question. In case a board or a MMC controller doesn't support 1.8V, it usually supports only 3.3V which is the intension of this patch. > > Rob > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan.wahren@i2se.com (Stefan Wahren) Date: Wed, 10 Aug 2016 22:27:04 +0200 (CEST) Subject: [PATCH RFC 1/3] DT: bindings: mmc: Add property for 3.3V only support In-Reply-To: <20160810184451.GA13473@rob-hp-laptop> References: <1470488140-10104-1-git-send-email-stefan.wahren@i2se.com> <1470488140-10104-2-git-send-email-stefan.wahren@i2se.com> <20160810184451.GA13473@rob-hp-laptop> Message-ID: <853617027.179290.63a6f478-ad48-40c8-82ca-760dd1afc040.open-xchange@email.1und1.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, > Rob Herring hat am 10. August 2016 um 20:44 geschrieben: > > > On Sat, Aug 06, 2016 at 12:55:38PM +0000, Stefan Wahren wrote: > > Currently there is no proper way to define that a MMC host supports > > only 3.3V. The property no-1-8-v is broken and has different meanings > > for different sdhci variants. So add a new property for 3.3V only > > support and mark no-1-8-v as deprecated. > > Why is it broken? i want to quote Ulf Hansson here [1]: The problem with the "no-1-8-v" binding is that it's describing what the hardware *can't* do. It thus becomes easy to abuse it. I suggest we stop using it, we should mark it deprecated. [1] - http://www.spinics.net/lists/linux-mmc/msg34604.html > How would I override a controller saying 1.8V is > supported and it is not? Sorry, i'm not sure that i understand your question. In case a board or a MMC controller doesn't support 1.8V, it usually supports only 3.3V which is the intension of this patch. > > Rob > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel