From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH v2] mmc: core: Allow specifying current consumption Date: Sat, 17 Oct 2015 10:09:38 -0700 Message-ID: <20151017170938.GP24668@usrtlx11787.corpusers.net> References: <1435725525-4367-1-git-send-email-bjorn.andersson@sonymobile.com> <1444698032-9051-1-git-send-email-bjorn.andersson@sonymobile.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ulf Hansson Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-mmc List-Id: linux-mmc@vger.kernel.org On Fri 16 Oct 05:55 PDT 2015, Ulf Hansson wrote: > On 13 October 2015 at 03:00, Bjorn Andersson > wrote: > > This allows us to specify expected current consumption of the vmmc and > > vqmmc regulators. This is needed to bring the supplying regulators out > > of their low-power-mode while accessing the mmc. > > This indeed makes sense, still I need to think a bit more on this. > Thanks. We can currently work around this by using "regulator-system-load" on the vmmc regulator, but a proper fix would be nice. > For example, can we allow these regulators to enter low power again at > some times? If so, when and what should that current value be. > The regulator framework recalculates the total load on a regulator upon enable/disable, but currently it doesn't depend on the state of the regulator. I talked to Mark about this a while back and he was positive to us correcting this, so disabled regulators wouldn't count towards the total load of a regulator. (So that still is on my todo) The second option would be to do what is done in the Qualcomm codeaurora kernels, where the regulators are never disabled and there's a smaller current specified for the suspend case. This would require bigger changes to the mmc core I presume, but the naming of the dt properties support such future adaption. > Moreover, wouldn't vmmc|vqmmc-active-current be depending what eMMC/SD > card that is attached? > I would say so, I do however not know how to acquire or encode that information. Any suggestions here are welcome. Regards, Bjorn -- 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