Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752948Ab0LOGlY (ORCPT ); Wed, 15 Dec 2010 01:41:24 -0500 Received: from cantor.suse.de ([195.135.220.2]:54775 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751793Ab0LOGlX (ORCPT ); Wed, 15 Dec 2010 01:41:23 -0500 Date: Wed, 15 Dec 2010 07:41:18 +0100 Message-ID: From: Takashi Iwai To: zhangfei gao Cc: Chris Ball , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Aries Lee , wuqm@marvell.com, Philip Rakity Subject: Re: [PATCH 2/2] mmc: Test bus-width for old MMC devices In-Reply-To: References: <1290579674-4616-1-git-send-email-tiwai@suse.de> <1290579674-4616-3-git-send-email-tiwai@suse.de> User-Agent: Wanderlust/2.15.6 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.7 Emacs/23.2 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8219 Lines: 186 At Tue, 14 Dec 2010 23:03:42 -0500, zhangfei gao wrote: > > On Wed, Nov 24, 2010 at 1:21 AM, Takashi Iwai wrote: > > From: Aries Lee > > > > Some old MMC devices fail with the 4/8 bits the driver tries to use > > exclusively.  This patch adds a test for the given bus setup and falls > > back to the lower bit mode (until 1-bit mode) when the test fails. > > > > [Major rework and refactoring by tiwai] > > > > Signed-off-by: Aries Lee > > Signed-off-by: Takashi Iwai > > --- > >  drivers/mmc/core/mmc.c     |   49 ++++++++++++--------- > >  drivers/mmc/core/mmc_ops.c |  102 ++++++++++++++++++++++++++++++++++++++++++++ > >  drivers/mmc/core/mmc_ops.h |    1 + > >  3 files changed, 131 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c > > index e81e6fe..5d8b4b2 100644 > > --- a/drivers/mmc/core/mmc.c > > +++ b/drivers/mmc/core/mmc.c > > @@ -507,29 +507,36 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, > >         */ > >        if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) && > >            (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) { > > -               unsigned ext_csd_bit, bus_width; > > - > > -               if (host->caps & MMC_CAP_8_BIT_DATA) { > > -                       ext_csd_bit = EXT_CSD_BUS_WIDTH_8; > > -                       bus_width = MMC_BUS_WIDTH_8; > > -               } else { > > -                       ext_csd_bit = EXT_CSD_BUS_WIDTH_4; > > -                       bus_width = MMC_BUS_WIDTH_4; > > +               static unsigned ext_csd_bits[] = { > > +                       EXT_CSD_BUS_WIDTH_8, > > +                       EXT_CSD_BUS_WIDTH_4, > > +                       EXT_CSD_BUS_WIDTH_1 > > +               }; > > +               static unsigned bus_widths[] = { > > +                       MMC_BUS_WIDTH_8, > > +                       MMC_BUS_WIDTH_4, > > +                       MMC_BUS_WIDTH_1 > > +               }; > > +               unsigned idx; > > + > > +               if (host->caps & MMC_CAP_8_BIT_DATA) > > +                       idx = 0; > > +               else > > +                       idx = 1; > > +               for (; idx < ARRAY_SIZE(bus_widths); idx++) { > > +                       err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, > > +                                        EXT_CSD_BUS_WIDTH, ext_csd_bits[idx]); > > +                       if (!err) { > > +                               mmc_set_bus_width(card->host, bus_widths[idx]); > > +                               err = mmc_bus_test(card, bus_widths[idx]); > > +                               if (!err) > > +                                       break; > > +                       } > >                } > > - > > -               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, > > -                                EXT_CSD_BUS_WIDTH, ext_csd_bit); > > - > > -               if (err && err != -EBADMSG) > > -                       goto free_card; > > - > >                if (err) { > > -                       printk(KERN_WARNING "%s: switch to bus width %d " > > -                              "failed\n", mmc_hostname(card->host), > > -                              1 << bus_width); > > -                       err = 0; > > -               } else { > > -                       mmc_set_bus_width(card->host, bus_width); > > +                       printk(KERN_WARNING "%s: switch to bus width failed\n", > > +                              mmc_hostname(card->host)); > > +                       goto free_card; > >                } > >        } > > > > diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c > > index 326447c..f8f47f9 100644 > > --- a/drivers/mmc/core/mmc_ops.c > > +++ b/drivers/mmc/core/mmc_ops.c > > @@ -462,3 +462,105 @@ int mmc_send_status(struct mmc_card *card, u32 *status) > >        return 0; > >  } > > > > +#define MMC_CMD_BUS_TEST_W             19 > > +#define MMC_CMD_BUS_TEST_R             14 > > + > > +static int > > +mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode, > > +                 u8 len) > > +{ > > +       struct mmc_request mrq; > > +       struct mmc_command cmd; > > +       struct mmc_data data; > > +       struct scatterlist sg; > > +       u8 *data_buf; > > +       u8 *test_buf; > > +       int i, err; > > +       static u8 testdata_8bit[8] = { 0x55, 0xaa, 0, 0, 0, 0, 0, 0 }; > > +       static u8 testdata_4bit[4] = { 0x5a, 0, 0, 0 }; > > + > > +       /* dma onto stack is unsafe/nonportable, but callers to this > > +        * routine normally provide temporary on-stack buffers ... > > +        */ > > +       data_buf = kmalloc(len, GFP_KERNEL); > > +       if (!data_buf) > > +               return -ENOMEM; > > + > > +       if (len == 8) > > +               test_buf = testdata_8bit; > > +       else if (len == 4) > > +               test_buf = testdata_4bit; > > +       else { > > +               printk(KERN_ERR "%s: Invaild bus_width %d\n", > > +                      mmc_hostname(host), len); > > +               return -EINVAL; > > +       } > > + > > +       if (opcode == MMC_CMD_BUS_TEST_W) > > +               memcpy(data_buf, test_buf, len); > > + > > +       memset(&mrq, 0, sizeof(struct mmc_request)); > > +       memset(&cmd, 0, sizeof(struct mmc_command)); > > +       memset(&data, 0, sizeof(struct mmc_data)); > > + > > +       mrq.cmd = &cmd; > > +       mrq.data = &data; > > +       cmd.opcode = opcode; > > +       cmd.arg = 0; > > + > > +       /* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we > > +        * rely on callers to never use this with "native" calls for reading > > +        * CSD or CID.  Native versions of those commands use the R2 type, > > +        * not R1 plus a data block. > > +        */ > > +       cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC; > > + > > +       data.blksz = len; > > +       data.blocks = 1; > > +       if (opcode == MMC_CMD_BUS_TEST_R) > > +               data.flags = MMC_DATA_READ; > > +       else > > +               data.flags = MMC_DATA_WRITE; > > + > > +       data.sg = &sg; > > +       data.sg_len = 1; > > +       sg_init_one(&sg, data_buf, len); > > +       mmc_wait_for_req(host, &mrq); > > +       err = 0; > > +       if (opcode == MMC_CMD_BUS_TEST_R) { > > +               for (i = 0; i < len / 4; i++) > > +                       if ((test_buf[i] ^ data_buf[i]) != 0xff) { > > +                               err = -EIO; > > +                               break; > > +                       } > > +       } > > +       kfree(data_buf); > > + > > +       if (cmd.error) > > +               return cmd.error; > > +       if (data.error) > > if (data.error && (data.error != -EILSEQ)) > Could you add code here to ignore CRC error of CMD14. > According to spec, CRC bits from card are optional in CMD14, and it is > ignored by host. > However some host still check and may get crc error here if card does not send. Philip corrected my patch and added such a check (in sdhci.c side). I'm going to resend the revised patch soon. thanks, Takashi -- 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/