At Tue, 14 Dec 2010 23:03:42 -0500, zhangfei gao wrote: > > On Wed, Nov 24, 2010 at 1:21 AM, Takashi Iwai <[email protected]> wrote: > > From: Aries Lee <[email protected]> > > > > 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 <[email protected]> > > Signed-off-by: Takashi Iwai <[email protected]> > > --- > > 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-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
