Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751290AbaLPSTD (ORCPT ); Tue, 16 Dec 2014 13:19:03 -0500 Received: from mail-la0-f42.google.com ([209.85.215.42]:47796 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985AbaLPSTA (ORCPT ); Tue, 16 Dec 2014 13:19:00 -0500 MIME-Version: 1.0 In-Reply-To: References: <54584260.8030602@nvidia.com> <545895B2.2000101@nvidia.com> Date: Tue, 16 Dec 2014 10:18:59 -0800 Message-ID: Subject: Re: Possible regression with commit 52221610d From: Bjorn Andersson To: Tim Kryger Cc: Ulf Hansson , Alexandre Courbot , Sachin Kamat , linux-mmc , "linux-kernel@vger.kernel.org" , Alexandre Courbot , linux-arm-msm Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 15, 2014 at 10:27 PM, Bjorn Andersson wrote: > On Sun, Dec 14, 2014 at 8:48 PM, Tim Kryger wrote: >> On Sat, Dec 13, 2014 at 11:22 PM, Bjorn Andersson wrote: > [..] >>> Or simply; what is vmmc (in the code) supposed to represent? >> >> Hi Bjorn, >> >> VMMC is the supply that delivers power out to the SD card itself (aka VDD). >> >> It is not the internal power rail/power domain of the host controller >> within the SoC. >> > > Thanks for you answer Tim, I'll write up a patch for the Qualcomm > driver that add the possibility of specifying an internal supply for > the devices where that uses that. > > My only concern is that for any standard compliant sdhci driver we're > supposed to have a info printout that vmmc was not found (but vqmmc is > there). But I guess that's a matter of proper documentation and hoping > people don't pay too much attention to it? > Sorry, this is wrong. We are routing the regulators straight to vdd of the memory and should hence use vmmc to specify this. However unless I actually program 0x29 in the Qualcomm sdhci block I get no responses from the card. Which I believe is correct behavior as the SDHC specification [1] says the following about BIT(0) of 0x29: "If this bit is cleared, the Host Controller shall immediately stop driving CMD and DAT[3:0] (tri-state) and drive SDCLK to low level". So I think 52221610d is indeed incorrect. [1] https://www.sdcard.org/downloads/pls/simplified_specs/archive/partA2_300.pdf Regards, Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/