On 01/11/14 09:23, Chanho Min wrote:
>>> So change the operating mode and to lower the clock.
>>
>> I meant something different.
>>
>> With your patch I find that __mmc_switch() -> send_status() fails.
>>
>> So I suggest something like this:
>>
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index 92247c2..195d48a 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -1045,21 +1045,28 @@ static int mmc_select_hs400(struct mmc_card *card)
>>      err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>>                         EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS,
>>                         card->ext_csd.generic_cmd6_time,
>> -                       true, true, true);
>> +                       true, false, false);
>> +    if (!err) {
>> +            u32 status;
>> +
>> +            /*
>> +             * According to JEDEC v5.01 spec (6.6.5), Clock frequency should
>> +             * be set to a value not greater than 52MHz after the HS_TIMING
>> +             * field is set to 0x1.
>> +            */
>> +            mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
>> +            mmc_set_bus_speed(card);
>> +
>> +            err = __mmc_send_status(card, &status, false, 1);
> 
> Why was retry-count changed to 1?
> Is there any reason not to use this?
> +               err = mmc_send_status(card, &status);

Error bits are cleared when read, so if the status command is not
successful then error information may have been lost.  So it does
not make sense to retry.

> 
> 
>> +            if (!err)
>> +                    err = mmc_check_switch_status(card->host, status);
>> +    }
>>      if (err) {
>>              pr_err("%s: switch to high-speed from hs200 failed, err:%d\n",
>>                      mmc_hostname(host), err);
>>              return err;
>>      }
>>
>> -    /*
>> -     * According to JEDEC v5.01 spec (6.6.5), Clock frequency should
>> -     * be set to a value not greater than 52MHz after the HS_TIMING
>> -     * field is set to 0x1.
>> -     */
>> -    mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
>> -    mmc_set_bus_speed(card);
>> -
>>      err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>>                       EXT_CSD_BUS_WIDTH,
>>                       EXT_CSD_DDR_BUS_WIDTH_8,
>> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
>> index 23aa3a3..f917527 100644
>> --- a/drivers/mmc/core/mmc_ops.c
>> +++ b/drivers/mmc/core/mmc_ops.c
>> @@ -23,15 +23,12 @@
>>
>>  #define MMC_OPS_TIMEOUT_MS  (10 * 60 * 1000) /* 10 minute timeout */
>>
>> -static inline int __mmc_send_status(struct mmc_card *card, u32 *status,
>> -                                bool ignore_crc)
>> +int __mmc_send_status(struct mmc_card *card, u32 *status, bool ignore_crc,
>> +                  int retries)
>>  {
>>      int err;
>>      struct mmc_command cmd = {0};
>>
>> -    BUG_ON(!card);
>> -    BUG_ON(!card->host);
>> -
>>      cmd.opcode = MMC_SEND_STATUS;
>>      if (!mmc_host_is_spi(card->host))
>>              cmd.arg = card->rca << 16;
>> @@ -39,7 +36,7 @@ static inline int __mmc_send_status(struct mmc_card *card, 
>> u32 *status,
>>      if (ignore_crc)
>>              cmd.flags &= ~MMC_RSP_CRC;
>>
>> -    err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
>> +    err = mmc_wait_for_cmd(card->host, &cmd, retries);
>>      if (err)
>>              return err;
>>
>> @@ -54,7 +51,7 @@ static inline int __mmc_send_status(struct mmc_card *card, 
>> u32 *status,
>>
>>  int mmc_send_status(struct mmc_card *card, u32 *status)
>>  {
>> -    return __mmc_send_status(card, status, false);
>> +    return __mmc_send_status(card, status, false, MMC_CMD_RETRIES);
>>  }
>>
>>  static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
>> @@ -419,6 +416,21 @@ int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
>>      return err;
>>  }
>>
>> +int mmc_check_switch_status(struct mmc_host *host, u32 status)
>> +{
>> +    if (mmc_host_is_spi(host)) {
>> +            if (status & R1_SPI_ILLEGAL_COMMAND)
>> +                    return -EBADMSG;
>> +    } else {
>> +            if (status & 0xFDFFA000)
>> +                    pr_warn("%s: unexpected status %#x after switch\n",
>> +                            mmc_hostname(host), status);
>> +            if (status & R1_SWITCH_ERROR)
>> +                    return -EBADMSG;
>> +    }
>> +    return 0;
>> +}
>> +
>>  /**
>>   *  __mmc_switch - modify EXT_CSD register
>>   *  @card: the MMC card associated with the data transfer
>> @@ -497,7 +509,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 
>> index, u8 value,
>>      timeout = jiffies + msecs_to_jiffies(timeout_ms);
>>      do {
>>              if (send_status) {
>> -                    err = __mmc_send_status(card, &status, ignore_crc);
>> +                    err = __mmc_send_status(card, &status, ignore_crc, 1);
>>                      if (err)
>>                              return err;
>>              }
>> @@ -524,18 +536,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 
>> index, u8 value,
>>              }
>>      } while (R1_CURRENT_STATE(status) == R1_STATE_PRG);
>>
>> -    if (mmc_host_is_spi(host)) {
>> -            if (status & R1_SPI_ILLEGAL_COMMAND)
>> -                    return -EBADMSG;
>> -    } else {
>> -            if (status & 0xFDFFA000)
>> -                    pr_warn("%s: unexpected status %#x after switch\n",
>> -                            mmc_hostname(host), status);
>> -            if (status & R1_SWITCH_ERROR)
>> -                    return -EBADMSG;
>> -    }
>> -
>> -    return 0;
>> +    return mmc_check_switch_status(host, status);
>>  }
>>  EXPORT_SYMBOL_GPL(__mmc_switch);
>>
>> diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
>> index 6f4b00e..a59319c 100644
>> --- a/drivers/mmc/core/mmc_ops.h
>> +++ b/drivers/mmc/core/mmc_ops.h
>> @@ -20,7 +20,10 @@ int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 
>> *rocr);
>>  int mmc_all_send_cid(struct mmc_host *host, u32 *cid);
>>  int mmc_set_relative_addr(struct mmc_card *card);
>>  int mmc_send_csd(struct mmc_card *card, u32 *csd);
>> +int __mmc_send_status(struct mmc_card *card, u32 *status, bool ignore_crc,
>> +                  int retries);
>>  int mmc_send_status(struct mmc_card *card, u32 *status);
>> +int mmc_check_switch_status(struct mmc_host *host, u32 status);
>>  int mmc_send_cid(struct mmc_host *host, u32 *cid);
>>  int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp);
>>  int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
> 
> Thanks
> Chanho
> 
> 
> 

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