Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755555AbaJNUEn (ORCPT ); Tue, 14 Oct 2014 16:04:43 -0400 Received: from mail-yh0-f53.google.com ([209.85.213.53]:49678 "EHLO mail-yh0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755434AbaJNUEl (ORCPT ); Tue, 14 Oct 2014 16:04:41 -0400 MIME-Version: 1.0 In-Reply-To: References: <1413000976-2038-1-git-send-email-dianders@chromium.org> From: Alim Akhtar Date: Wed, 15 Oct 2014 01:34:00 +0530 Message-ID: Subject: Re: [PATCH] mmc: dw_mmc: Change signal voltage error to dev_dbg() To: Doug Anderson Cc: Ulf Hansson , Seungwon Jeon , Jaehoon Chung , Addy Ke , Sonny Rao , Alim Akhtar , Chris Ball , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.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 Hi Doug, On Tue, Oct 14, 2014 at 9:57 PM, Doug Anderson wrote: > Alim, > > On Tue, Oct 14, 2014 at 5:02 AM, Alim Akhtar wrote: >>> --- a/drivers/mmc/host/dw_mmc.c >>> +++ b/drivers/mmc/host/dw_mmc.c >>> @@ -1075,7 +1075,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) >>> ret = regulator_set_voltage(mmc->supply.vqmmc, min_uv, max_uv); >>> >>> if (ret) { >>> - dev_err(&mmc->class_dev, >>> + dev_dbg(&mmc->class_dev, >>> "Regulator set error %d: %d - %d\n", >>> ret, min_uv, max_uv); >>> return ret; >> Well, I am ok with this but this info is very useful, what if PMIC >> failed to actually set the voltage? may be because of some PMIC driver >> bug or i2c driver bug? Ofcourse this can be found by turning MMC_DEBUG >> ON, but is that worth in this case. Or is there a way to print that, >> this failure is because of a regulator re-try? >> your thoughts? > > I think that the regulator framework and the i2c framework are > supposed to be reliable. If they aren't reliable there will be lots > of places that will have problems. I think that you _could_: > > * In your regulator driver print an error when an i2c transfer fails. > > * In your regulator driver print an error if some unexpected event > happens (like a regulator reports that the voltage didn't actually > change). > > That would get you want you want, right? ...but an error here doesn't > belong and that's pretty much determined by (28f92b5 mmc: core: Try > other signal levels during power up). That patch wants to be able to > try several different voltage levels and if we print an error in that > case then it's going to be very confusing to the user. > Hmm...Ok, convincing enough to me, so Reviewed-by: Alim Akhtar > -Doug -- Regards, Alim -- 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/