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From:   Chunyan Zhang <zhang.lyra@gmail.com>
Date:   Wed, 29 Aug 2018 19:39:47 +0800
Message-ID: <CAAfSe-s-W467D2dk-_7AWQz9ZaysROf5otoN-o-yu3Eu5ZVC4g@mail.gmail.com>
Subject: Re: [PATCH V7 7/9] mmc: sdhci: SDMA may use Auto-CMD23 in v4 mode
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     Chunyan Zhang <zhang.chunyan@linaro.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        linux-mmc@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Orson Zhai <orsonzhai@gmail.com>,
        Baolin Wang <baolin.wang@linaro.org>,
        Billows Wu <billows.wu@unisoc.com>,
        Jason Wu <jason.wu@unisoc.com>,
        Chunyan Zhang <chunyan.zhang@unisoc.com>
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On 29 August 2018 at 18:59, Adrian Hunter <adrian.hunter@intel.com> wrote:
> On 29/08/18 10:03, Chunyan Zhang wrote:
>> When Host Version 4 Enable is set to 1, SDMA uses ADMA System Address
>> register (05Fh-058h) instead of using register (000h-004h) to indicate
>> its system address of data location. The register (000h-004h) is
>> re-assigned to 32-bit Block Count and Auto CMD23 argument, so then SDMA
>> may use Auto CMD23.
>>
>> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
>> ---
>>  drivers/mmc/host/sdhci.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 62d843ac90..ac92e0f 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -3834,10 +3834,14 @@ int sdhci_setup_host(struct sdhci_host *host)
>>       if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12)
>>               host->flags |= SDHCI_AUTO_CMD12;
>>
>> -     /* Auto-CMD23 stuff only works in ADMA or PIO. */
>> +     /*
>> +      * For v3 mode, Auto-CMD23 stuff only works in ADMA or PIO;
>
> ; -> .
>
>> +      * For v4 mode, SDMA may use Auto-CMD23 as well.
>> +      */
>>       if ((host->version >= SDHCI_SPEC_300) &&
>>           ((host->flags & SDHCI_USE_ADMA) ||
>> -          !(host->flags & SDHCI_USE_SDMA)) &&
>> +          (!host->v4_mode && !(host->flags & SDHCI_USE_SDMA)) ||
>> +          (host->v4_mode && (host->flags & SDHCI_USE_SDMA))) &&
>>            !(host->quirks2 & SDHCI_QUIRK2_ACMD23_BROKEN)) {
>
> This is over complicated.  We can use auto-CMD23 if not using SDMA or if in
> v4_mode i.e.
>
>         if (host->version >= SDHCI_SPEC_300 &&
>             (!(host->flags & SDHCI_USE_SDMA) || host->v4_mode) &&
>             !(host->quirks2 & SDHCI_QUIRK2_ACMD23_BROKEN)) {
>

So no matter whether SDHCI_USE_ADMA is selected, right?

>>               host->flags |= SDHCI_AUTO_CMD23;
>>               DBG("Auto-CMD23 available\n");
>>
>