Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752194Ab0LUQje (ORCPT ); Tue, 21 Dec 2010 11:39:34 -0500 Received: from na3sys009aog103.obsmtp.com ([74.125.149.71]:37725 "HELO na3sys009aog103.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751020Ab0LUQjd convert rfc822-to-8bit (ORCPT ); Tue, 21 Dec 2010 11:39:33 -0500 From: Philip Rakity To: zhangfei gao CC: Takashi Iwai , Chris Ball , Aries Lee , Qiming Wu , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Tue, 21 Dec 2010 08:36:22 -0800 Subject: Re: [PATCH] mmc: Test bus-width for old MMC devices (v2) Thread-Topic: [PATCH] mmc: Test bus-width for old MMC devices (v2) Thread-Index: AcuhLTVYJ0RCpNpWQzS1UDlXGQu+tg== Message-ID: References: <20101216234032.GA17239@void.printf.net> <50D31EC8-BD9E-4920-8CEB-2AD10DF9C5C5@marvell.com> <20101217034342.GA19673@void.printf.net> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3556 Lines: 120 Can you please try this diff and see if it works for you. Will do formal patch after your testing. What card is failing ? Please let me know the manufacturing information so can add card to my test suite. Philip diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 1d8409f..77072c8 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -558,6 +558,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, EXT_CSD_BUS_WIDTH, ext_csd_bits[idx][0]); if (!err) { + mmc_set_bus_width_ddr(card->host, + bus_width, MMC_SDR_MODE); /* * If controller can't handle bus width test, * use the highest bus width to maintain @@ -565,8 +567,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, */ if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)) break; - mmc_set_bus_width_ddr(card->host, - bus_width, MMC_SDR_MODE); err = mmc_bus_test(card, bus_width); if (!err) break; @@ -586,7 +586,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, } else if (ddr) { mmc_card_set_ddr_mode(card); mmc_set_bus_width_ddr(card->host, bus_width, ddr); - } + } else + mmc_set_bus_width (card->host, bus_width); } if (!oldcard) Philip On Dec 21, 2010, at 2:59 AM, zhangfei gao wrote: > On Fri, Dec 17, 2010 at 3:11 AM, Takashi Iwai wrote: >> At Fri, 17 Dec 2010 03:43:42 +0000, >> Chris Ball wrote: >>> >>> Hi Philip, >>> >>> On Thu, Dec 16, 2010 at 06:33:49PM -0800, Philip Rakity wrote: >>>> It is not possible for bus_width to be not initialized. This would imply ARRAY_SIZE(bus_widths) is 1. Certainly not true. >>> >>> Right, I agree. We should fix the warning anyway. >> >> Well, this is always a gray-zone question. One prefers fixing it >> either via uninitialized_var() or by setting a bogus value. But, this >> would cover any possible real bug in future. Thus another prefers >> ignoring it, because it's just a compiler bug (mostly of old gcc). >> >> After all, it's up to maintainer, so take as you like :) >> >> >> thanks, >> >> Takashi >> >> >>>> We could just initialize by changing >>>> + unsigned idx, bus_width; >>>> to >>>> + unsigned idx, bus_width = 0; >>> >>> Okay, I've pushed to mmc-next with that change. >>> >>>> I wonder what compiler are you using so we can avoid this issue in future. >>> >>> Ah, good point -- I was building with a gcc 4.1.2 ARM cross-compiler, >>> and using a gcc 4.5.1 cross-build instead avoids the warning. >>> >>> Thanks, >>> >>> -- >>> Chris Ball >>> One Laptop Per Child >>> >> > > Could you help adding this modification? > We found error happen since bus_width is not set at these condition: > 1. ddr=0 > 2. not set MMC_CAP_BUS_WIDTH_TEST > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > index 1d8409f..86cac0d 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -586,7 +586,11 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, > } else if (ddr) { > mmc_card_set_ddr_mode(card); > mmc_set_bus_width_ddr(card->host, bus_width, ddr); > - } > + > + } else > + mmc_set_bus_width(card->host, > + bus_widths[idx]); > + > } > > if (!oldcard) -- 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/