Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752969Ab2EOFMx (ORCPT ); Tue, 15 May 2012 01:12:53 -0400 Received: from na3sys009aog130.obsmtp.com ([74.125.149.143]:51528 "EHLO na3sys009aog130.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751710Ab2EOFMw convert rfc822-to-8bit (ORCPT ); Tue, 15 May 2012 01:12:52 -0400 From: Yong Ding To: Philip Rakity CC: "cjb@laptop.org" , "linux-mmc@vger.kernel.org" , "ohad@wizery.com" , "linus.walleij@linaro.org" , "ulf.hansson@stericsson.com" , "linux-kernel@vger.kernel.org" Date: Mon, 14 May 2012 22:12:34 -0700 Subject: RE: [PATCH] mmc:sdio:guarantee setting card data bus width as 4-bit Thread-Topic: [PATCH] mmc:sdio:guarantee setting card data bus width as 4-bit Thread-Index: Ac0x2w19O8a6sSP8R12jR/qLrJN3mQAff8zg Message-ID: <89813612683626448B837EE5A0B6A7CB1A2B9F19F5@SC-VEXCH4.marvell.com> References: <1336984510-9723-1-git-send-email-yongd@marvell.com> In-Reply-To: Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: zh-CN, 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: 2952 Lines: 90 Philip, Thanks for your comment. And have sent out "[PATCH v2] mmc:sdio:guarantee setting card data bus width as 4-bit " which uses the below printk. printk(KERN_WARNING("%s: SDIO_CCCR_IF is invalid: 0x%02X\n", mmc_hostname(card->host), ctrl); Best Wishes, Yong Ding Operating Systems Engineering, Application Processor Systems Engineering -----Original Message----- From: Philip Rakity Sent: Monday, May 14, 2012 10:09 PM To: Yong Ding Cc: cjb@laptop.org; linux-mmc@vger.kernel.org; ohad@wizery.com; linus.walleij@linaro.org; ulf.hansson@stericsson.com; linux-kernel@vger.kernel.org Subject: Re: [PATCH] mmc:sdio:guarantee setting card data bus width as 4-bit ACK but see below for printk change On May 14, 2012, at 1:35 AM, yongd wrote: > SDIO_CCCR_IF[1:0] in SDIO card is used for card data bus width > setting as below, > 00b: 1-bit bus > 01b: Reserved > 10b: 4-bit bus > 11b: 8-bit bus(only for embedded SDIO) > And sdio_enable_wide is for setting data bus width as 4-bit. But > currently, it 1stly read the register, 2ndly OR' 1b with SDIO_CCCR_IF[1], > and then write it back. > As we can see, such way is based on such assumption that the > SDIO_CCCR_IF[0] is always 0. Apparently, this is not right. > > Signed-off-by: yongd > --- > drivers/mmc/core/sdio.c | 6 ++++++ > include/linux/mmc/sdio.h | 2 ++ > 2 files changed, 8 insertions(+) > > diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c > index 13d0e95..6b6f902 100644 > --- a/drivers/mmc/core/sdio.c > +++ b/drivers/mmc/core/sdio.c > @@ -218,6 +218,12 @@ static int sdio_enable_wide(struct mmc_card *card) > if (ret) > return ret; > > + if ((ctrl & SDIO_BUS_WIDTH_MASK) > + == SDIO_BUS_WIDTH_RESERVED) > + printk(KERN_WARNING"SDIO_CCCR_IF is invalid: %d\n", ctrl); printk(KERN_WARNING("%s: SDIO_CCCR_IF is invalid: %02X\n", mmc_hostname(card->host), ctrl); please double check mmc_hostname argument. > + > + /* set as 4-bit bus width */ > + ctrl &= ~SDIO_BUS_WIDTH_MASK; > ctrl |= SDIO_BUS_WIDTH_4BIT; > > ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL); > diff --git a/include/linux/mmc/sdio.h b/include/linux/mmc/sdio.h > index c9fe66c..17446d3 100644 > --- a/include/linux/mmc/sdio.h > +++ b/include/linux/mmc/sdio.h > @@ -98,7 +98,9 @@ > > #define SDIO_CCCR_IF 0x07 /* bus interface controls */ > > +#define SDIO_BUS_WIDTH_MASK 0x03 /* data bus width setting */ > #define SDIO_BUS_WIDTH_1BIT 0x00 > +#define SDIO_BUS_WIDTH_RESERVED 0x01 > #define SDIO_BUS_WIDTH_4BIT 0x02 > #define SDIO_BUS_ECSI 0x20 /* Enable continuous SPI interrupt */ > #define SDIO_BUS_SCSI 0x40 /* Support continuous SPI interrupt */ > -- > 1.7.9.5 > -- 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/