Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754745AbbLKOsI (ORCPT ); Fri, 11 Dec 2015 09:48:08 -0500 Received: from mail-qk0-f170.google.com ([209.85.220.170]:36288 "EHLO mail-qk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753305AbbLKOsG (ORCPT ); Fri, 11 Dec 2015 09:48:06 -0500 MIME-Version: 1.0 In-Reply-To: <1449840989-563-1-git-send-email-jszhang@marvell.com> References: <1449840989-563-1-git-send-email-jszhang@marvell.com> Date: Fri, 11 Dec 2015 15:48:04 +0100 Message-ID: Subject: Re: [PATCH v2] mmc: sdhci: restore behavior when setting VDD via external regulator From: Ulf Hansson To: Jisheng Zhang , Ludovic Desroches Cc: linux-mmc , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3666 Lines: 92 + Ludovic (We had some discussions around this code recently as well) On 11 December 2015 at 14:36, Jisheng Zhang wrote: > After commit 52221610dd84 ("mmc: sdhci: Improve external VDD regulator > support"), for the VDD is supplied via external regulators, we ignore > the code to convert a VDD voltage request into one of the standard > SDHCI voltage levels, then program it in the SDHCI_POWER_CONTROL. This > brings two issues: > > 1. SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON quirk isn't handled properly any > more. > > 2. What's more, once SDHCI_POWER_ON bit is set, some controllers such > as the sdhci-pxav3 used in marvell berlin SoCs require the voltage > levels programming in the SDHCI_POWER_CONTROL register, even the VDD > is supplied by external regulator. So the host in marvell berlin SoCs > still works fine after the commit. However, commit 3cbc6123a93d ("mmc: > sdhci: Set SDHCI_POWER_ON with external vmmc") sets the SDHCI_POWER_ON > bit, this would make the host in marvell berlin SoCs won't work any > more with external vmmc. > > This patch restores the behavior when setting VDD through external > regulator by moving the call of mmc_regulator_set_ocr() to the end > of sdhci_set_power() function. > > After this patch, the sdcard on Marvell Berlin SoC boards work again. > > Signed-off-by: Jisheng Zhang > Fixes: 52221610dd84 ("mmc: sdhci: Improve external VDD ...") > --- > Since v1: > - add more details about why the sdhci-pxav3 used in marvell berlin > SoCs need this patch. > > drivers/mmc/host/sdhci.c | 19 ++++++------------- > 1 file changed, 6 insertions(+), 13 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index b48565e..616aa90 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -1274,19 +1274,6 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode, > struct mmc_host *mmc = host->mmc; > u8 pwr = 0; > > - if (!IS_ERR(mmc->supply.vmmc)) { > - spin_unlock_irq(&host->lock); > - mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd); > - spin_lock_irq(&host->lock); > - > - if (mode != MMC_POWER_OFF) > - sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL); > - else > - sdhci_writeb(host, 0, SDHCI_POWER_CONTROL); > - > - return; > - } > - > if (mode != MMC_POWER_OFF) { > switch (1 << vdd) { > case MMC_VDD_165_195: > @@ -1345,6 +1332,12 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode, > if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER) > mdelay(10); > } > + > + if (!IS_ERR(mmc->supply.vmmc)) { > + spin_unlock_irq(&host->lock); > + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd); > + spin_lock_irq(&host->lock); > + } > } > > /*****************************************************************************\ > -- > 2.6.3 > My concern with this patch is that it might fix the problem for your SDHCI variant, but will break it for others. I guess we can give it try, unless or until someone reports a problem. Although, I would like to get Ludovic's input on this change, before I decide to do anything. Kind regards Uffe -- 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/