From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754774Ab0IEUoF (ORCPT ); Sun, 5 Sep 2010 16:44:05 -0400 Received: from void.printf.net ([89.145.121.20]:47079 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754502Ab0IEUoE (ORCPT ); Sun, 5 Sep 2010 16:44:04 -0400 Date: Sun, 5 Sep 2010 21:43:36 +0100 From: Chris Ball To: Matt Fleming Cc: Hein_Tibosch , Andrew Morton , Pierre Ossman , Chris Ball , Ben Nizette , Sascha Hauer , Adrian Hunter , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] mmc: Make ID freq configurable Message-ID: <20100905204336.GA23574@void.printf.net> References: <4C80187D.9000304@yahoo.es> <20100905201448.GA22819@console-pimps.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100905201448.GA22819@console-pimps.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matt, On Sun, Sep 05, 2010 at 09:14:48PM +0100, Matt Fleming wrote: > On Fri, Sep 03, 2010 at 05:34:53AM +0800, Hein_Tibosch wrote: > > In the latest releases of the mmc driver, the freq during initialization > > is set to a fixed 400 Khz. This was reportedly too fast for several > > users. As there doesn't seem to be an ideal frequency which-works-for-all, > > Pierre suggested to let the driver try several frequencies. > > > > This patch implements that idea. It will try mmc-initialization using > > several frequencies from an array 400, 300, 200 and 100. > > I submitted it earlier but it's now adapted to and tested with kernel > > 2.6.36-rc3. > > > > In case SDIO is broken, it'll still try to detect SDMEM, also at different > > freqs. > > > > Signed-off-by: Hein Tibosch > > > > --- > > diff -Nurp a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > > --- a/drivers/mmc/core/core.c 2010-08-29 23:36:04.000000000 +0800 > > +++ b/drivers/mmc/core/core.c 2010-09-03 04:28:52.000000000 +0800 > > @@ -907,12 +907,7 @@ static void mmc_power_up(struct mmc_host > > */ > > mmc_delay(10); > > > > - if (host->f_min > 400000) { > > - pr_warning("%s: Minimum clock frequency too high for " > > - "identification mode\n", mmc_hostname(host)); > > - host->ios.clock = host->f_min; > > - } else > > - host->ios.clock = 400000; > > + host->ios.clock = host->f_init; > > > > host->ios.power_mode = MMC_POWER_ON; > > mmc_set_ios(host); > > @@ -1404,6 +1399,8 @@ void mmc_rescan(struct work_struct *work > > u32 ocr; > > int err; > > unsigned long flags; > > + int i; > > + unsigned freqs[] = { 400000, 300000, 200000, 100000 }; > > > > spin_lock_irqsave(&host->lock, flags); > > > > @@ -1443,55 +1440,64 @@ void mmc_rescan(struct work_struct *work > > if (host->ops->get_cd && host->ops->get_cd(host) == 0) > > goto out; > > > > - mmc_claim_host(host); > > + for (i = 0; i < ARRAY_SIZE(freqs); i++) { > > + mmc_claim_host(host); > > > > - mmc_power_up(host); > > - sdio_reset(host); > > - mmc_go_idle(host); > > + if (freqs[i] >= host->f_min) > > + host->f_init = freqs[i]; > > + else if (i && freqs[i-1] <= host->f_min) > > + goto out; > > The label 'out' does not release the claim on the host. Thanks for catching that. > > + else > > + host->f_init = host->f_min; > > > > - mmc_send_if_cond(host, host->ocr_avail); > > + printk ("mmc_rescan: trying %u Hz\n", host->f_init); > > + mmc_power_up(host); > > + sdio_reset(host); > > + mmc_go_idle(host); > > > > - /* > > - * First we search for SDIO... > > - */ > > - err = mmc_send_io_op_cond(host, 0, &ocr); > > - if (!err) { > > - if (mmc_attach_sdio(host, ocr)) { > > - mmc_claim_host(host); > > - /* try SDMEM (but not MMC) even if SDIO is broken */ > > - if (mmc_send_app_op_cond(host, 0, &ocr)) > > - goto out_fail; > > + mmc_send_if_cond(host, host->ocr_avail); > > + > > + /* > > + * First we search for SDIO... > > + */ > > + err = mmc_send_io_op_cond(host, 0, &ocr); > > + if (!err) { > > + if (mmc_attach_sdio(host, ocr)) { > > + mmc_claim_host(host); > > + /* try SDMEM (but not MMC) even if SDIO is broken */ > > + if (mmc_send_app_op_cond(host, 0, &ocr)) > > + goto out_fail; > > + > > + if (mmc_attach_sd(host, ocr)) > > + mmc_power_off(host); > > + } > > + goto out; > > + } > > > > + /* > > + * ...then normal SD... > > + */ > > + err = mmc_send_app_op_cond(host, 0, &ocr); > > + if (!err) { > > if (mmc_attach_sd(host, ocr)) > > mmc_power_off(host); > > + goto out; > > Same problem here. > > > } > > - goto out; > > - } > > > > - /* > > - * ...then normal SD... > > - */ > > - err = mmc_send_app_op_cond(host, 0, &ocr); > > - if (!err) { > > - if (mmc_attach_sd(host, ocr)) > > - mmc_power_off(host); > > - goto out; > > - } > > - > > - /* > > - * ...and finally MMC. > > - */ > > - err = mmc_send_op_cond(host, 0, &ocr); > > - if (!err) { > > - if (mmc_attach_mmc(host, ocr)) > > - mmc_power_off(host); > > - goto out; > > - } > > + /* > > + * ...and finally MMC. > > + */ > > + err = mmc_send_op_cond(host, 0, &ocr); > > + if (!err) { > > + if (mmc_attach_mmc(host, ocr)) > > + mmc_power_off(host); > > + goto out; > > + } > > And here. Actually, mmc_attach_{sd,mmc}() both do release the host as part of their failure case, so I don't think there's a problem with these two. - Chris. -- Chris Ball One Laptop Per Child