Re: [PATCH V4 5/7] mmc: sdhci: add Auto CMD Auto Select support

[Adrian Hunter <adrian.hunter@intel.com>]

On 31/07/18 12:20, Chunyan Zhang wrote:
> On 31 July 2018 at 16:56, Adrian Hunter <adrian.hunter@intel.com> wrote:
>> On 31/07/18 11:36, Chunyan Zhang wrote:
>>> On 31 July 2018 at 16:05, Adrian Hunter <adrian.hunter@intel.com> wrote:
>>>> On 31/07/18 10:04, Chunyan Zhang wrote:
>>>>> Hi Adrian,
>>>>>
>>>>> On 30 July 2018 at 21:06, Adrian Hunter <adrian.hunter@intel.com> wrote:
>>>>>> On 23/07/18 13:08, Chunyan Zhang wrote:
>>>>>>> As SD Host Controller Specification v4.10 documents:
>>>>>>> Host Controller Version 4.10 defines this "Auto CMD Auto Select" mode.
>>>>>>> Selection of Auto CMD depends on setting of CMD23 Enable in the Host
>>>>>>> Control 2 register which indicates whether card supports CMD23. If CMD23
>>>>>>> Enable =1, Auto CMD23 is used and if CMD23 Enable =0, Auto CMD12 is
>>>>>>> used. In case of Version 4.10 or later, use of Auto CMD Auto Select is
>>>>>>> recommended rather than use of Auto CMD12 Enable or Auto CMD23
>>>>>>> Enable.
>>>>>>>
>>>>>>> This patch add this new mode support.
>>>>>>>
>>>>>>> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
>>>>>>> ---
>>>>>>>  drivers/mmc/host/sdhci.c | 61 +++++++++++++++++++++++++++++++++++++++---------
>>>>>>>  drivers/mmc/host/sdhci.h |  2 ++
>>>>>>>  2 files changed, 52 insertions(+), 11 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>>>>>> index 5acea3d..5c60590 100644
>>>>>>> --- a/drivers/mmc/host/sdhci.c
>>>>>>> +++ b/drivers/mmc/host/sdhci.c
>>>>>>> @@ -311,6 +311,23 @@ static void sdhci_config_dma(struct sdhci_host *host)
>>>>>>>       sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
>>>>>>>  }
>>>>>>>
>>>>>>> +static void sdhci_enable_cmd23(struct sdhci_host *host)
>>>>>>> +{
>>>>>>> +     u16 ctrl2;
>>>>>>> +
>>>>>>> +     /*
>>>>>>> +      * This is used along with "Auto CMD Auto Select" feature,
>>>>>>> +      * which is introduced from v4.10, if card supports CMD23,
>>>>>>> +      * Auto CMD23 should be used instead of Auto CMD12.
>>>>>>> +      */
>>>>>>> +     if (host->version >= SDHCI_SPEC_410 &&
>>>>>>> +         (host->mmc->caps & MMC_CAP_CMD23)) {
>>>>>>
>>>>>> That is the host capability.  It needs to be the card capability.
>>>>>
>>>>> Could you please elaborate the issue?
>>>>>
>>>>> I thought we're setting for host here.  Do you mean we need to see the
>>>>> card capability?
>>>>
>>>> Yes. SDHCI_TRNS_AUTO_SEL selects auto-CMD23 or auto-CMD12 based on this
>>>> setting, so this must reflect the card's capability.
>>>
>>> Got it, but how to know if the card supports CMD23?
>>
>> At the moment the only way of knowing is if a request is received with mrq->sbc
>>
>>>
>>>>
>>>>>
>>>>>>
>>>>>>> +             ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>>>>>> +             ctrl2 |= SDHCI_CMD23_ENABLE;
>>>>>>> +             sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);
>>>>>>> +     }
>>>>>>> +}
>>>>>>> +
>>>>>>>  static void sdhci_init(struct sdhci_host *host, int soft)
>>>>>>>  {
>>>>>>>       struct mmc_host *mmc = host->mmc;
>>>>>>> @@ -329,6 +346,8 @@ static void sdhci_init(struct sdhci_host *host, int soft)
>>>>>>>               host->clock = 0;
>>>>>>>               mmc->ops->set_ios(mmc, &mmc->ios);
>>>>>>>       }
>>>>>>> +
>>>>>>> +     sdhci_enable_cmd23(host);
>>>>>>>  }
>>>>>>>
>>>>>>>  static void sdhci_reinit(struct sdhci_host *host)
>>>>>>> @@ -1093,6 +1112,36 @@ static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
>>>>>>>              !mrq->cap_cmd_during_tfr;
>>>>>>>  }
>>>>>>>
>>>>>>> +static inline void sdhci_auto_cmd_select(struct sdhci_host *host,
>>>>>>> +                                      struct mmc_command *cmd,
>>>>>>> +                                      u16 *mode)
>>>>>>> +{
>>>>>>> +     bool use_cmd12 = sdhci_auto_cmd12(host, cmd->mrq) &&
>>>>>>> +                      (cmd->opcode != SD_IO_RW_EXTENDED);
>>>>>>> +     bool use_cmd23 = cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23);
>>>>>>> +
>>>>>>> +     /*
>>>>>>> +      * In case of Version 4.10 or later, use of 'Auto CMD Auto
>>>>>>> +      * Select' is recommended rather than use of 'Auto CMD12
>>>>>>> +      * Enable' or 'Auto CMD23 Enable'.
>>>>>>> +      */
>>>>>>> +     if (host->version >= SDHCI_SPEC_410 && (use_cmd12 || use_cmd23)) {
>>>>>>> +             *mode |= SDHCI_TRNS_AUTO_SEL;
>>>>>>
>>>>>> As noted in patch 4, the CMD23 argument is not just the block count for eMMC.
>>>>>
>>>>> Probably I haven't got your point...
>>>>>
>>>>> >From what I understand, auto_sel mode doesn't need argument2. Doesn't
>>>>> this work for eMMC?
>>>>
>>>> CMD23 always needs an argument
>>>
>>> But setting argument for CMD23 will cover the block count value we set
>>> before, that will lead mounting emmc to fail.
>>
>> Does it fail because it contains cmd->mrq->sbc->arg or does it fail because
>> it gets written twice?
> 
> Seems that the argument is too big compared with block count, hardware
> think it is a super block count.
> 
> More details of the error information:
> https://www.irccloud.com/pastebin/uYlVEUsP/

Does it work with auto-CMD23 instead of auto-CMD-auto-select?
Does it work if the 16-bit block count register is used?

Obviously, if we can't pass the CMD23 argument correctly then we can't use
auto-CMD23.

> 
>>
>>>
>>>>
>>>>>
>>>>> The test platform I used was just eMMC only, haven't found problem.
>>>>
>>>> Because the bits that are missing from the CMD23 argument (reliable write,
>>>> context id, etc) will not make the command fail.
>>>>
>>>>>
>>>>> Thanks,
>>>>> Chunyan
>>>>>
>>>>>>
>>>>>>> +             return;
>>>>>>> +     }
>>>>>>> +
>>>>>>> +     /*
>>>>>>> +      * If we are sending CMD23, CMD12 never gets sent
>>>>>>> +      * on successful completion (so no Auto-CMD12).
>>>>>>> +      */
>>>>>>> +     if (use_cmd12) {
>>>>>>> +             *mode |= SDHCI_TRNS_AUTO_CMD12;
>>>>>>> +     } else if (use_cmd23) {
>>>>>>> +             *mode |= SDHCI_TRNS_AUTO_CMD23;
>>>>>>> +             sdhci_writel(host, cmd->mrq->sbc->arg, SDHCI_ARGUMENT2);
>>>>>>> +     }
>>>>>>> +}
>>>>>>> +
>>>>>>>  static void sdhci_set_transfer_mode(struct sdhci_host *host,
>>>>>>>       struct mmc_command *cmd)
>>>>>>>  {
>>>>>>> @@ -1119,17 +1168,7 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
>>>>>>>
>>>>>>>       if (mmc_op_multi(cmd->opcode) || data->blocks > 1) {
>>>>>>>               mode = SDHCI_TRNS_BLK_CNT_EN | SDHCI_TRNS_MULTI;
>>>>>>> -             /*
>>>>>>> -              * If we are sending CMD23, CMD12 never gets sent
>>>>>>> -              * on successful completion (so no Auto-CMD12).
>>>>>>> -              */
>>>>>>> -             if (sdhci_auto_cmd12(host, cmd->mrq) &&
>>>>>>> -                 (cmd->opcode != SD_IO_RW_EXTENDED))
>>>>>>> -                     mode |= SDHCI_TRNS_AUTO_CMD12;
>>>>>>> -             else if (cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
>>>>>>> -                     mode |= SDHCI_TRNS_AUTO_CMD23;
>>>>>>> -                     sdhci_writel(host, cmd->mrq->sbc->arg, SDHCI_ARGUMENT2);
>>>>>>> -             }
>>>>>>> +             sdhci_auto_cmd_select(host, cmd, &mode);
>>>>>>>       }
>>>>>>>
>>>>>>>       if (data->flags & MMC_DATA_READ)
>>>>>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>>>>>> index 81aae07..a8f4ec2 100644
>>>>>>> --- a/drivers/mmc/host/sdhci.h
>>>>>>> +++ b/drivers/mmc/host/sdhci.h
>>>>>>> @@ -42,6 +42,7 @@
>>>>>>>  #define  SDHCI_TRNS_BLK_CNT_EN       0x02
>>>>>>>  #define  SDHCI_TRNS_AUTO_CMD12       0x04
>>>>>>>  #define  SDHCI_TRNS_AUTO_CMD23       0x08
>>>>>>> +#define  SDHCI_TRNS_AUTO_SEL 0x0C
>>>>>>>  #define  SDHCI_TRNS_READ     0x10
>>>>>>>  #define  SDHCI_TRNS_MULTI    0x20
>>>>>>>
>>>>>>> @@ -185,6 +186,7 @@
>>>>>>>  #define   SDHCI_CTRL_DRV_TYPE_D              0x0030
>>>>>>>  #define  SDHCI_CTRL_EXEC_TUNING              0x0040
>>>>>>>  #define  SDHCI_CTRL_TUNED_CLK                0x0080
>>>>>>> +#define  SDHCI_CMD23_ENABLE          0x0800
>>>>>>>  #define  SDHCI_CTRL_V4_MODE          0x1000
>>>>>>>  #define  SDHCI_CTRL_64BIT_ADDR               0x2000
>>>>>>>  #define  SDHCI_CTRL_PRESET_VAL_ENABLE        0x8000
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>