[PATCH v3 3/3] configs: rpi_4_32b_defconfig: enable SDHCI_SDMA config

[Jaehoon Chung]

On 3/26/20 1:09 AM, Matthias Brugger wrote:
> 
> 
> On 24/03/2020 23:58, Jaehoon Chung wrote:
>> Enable SDHCI_SDMA configuration.
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung at samsung.com>
>> Reviewed-by: Peng Fan <peng.fan at nxp.com>
>> Reviewed-by: Minkyu Kang <mk7.kang at samsung.com>
>> ---
>>  configs/rpi_4_32b_defconfig | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/configs/rpi_4_32b_defconfig b/configs/rpi_4_32b_defconfig
>> index 72cda5d949..7189914606 100644
>> --- a/configs/rpi_4_32b_defconfig
>> +++ b/configs/rpi_4_32b_defconfig
>> @@ -25,6 +25,7 @@ CONFIG_DFU_MMC=y
>>  CONFIG_DM_KEYBOARD=y
>>  CONFIG_DM_MMC=y
>>  CONFIG_MMC_SDHCI=y
>> +CONFIG_MMC_SDHCI_SDMA=y
> 
> RPi4 can only do DMA transfers to the first GiB of memory. I wasn't sucessfull
> in understanding the mmc/sdhci code to see where we take the dma-ranges property
> into account so that we don't use an address > 1 GiB.

Sorry i don't understand clearly what you said.

> 
> Are we safe in this regard? If we are, then we can also enable this for
> rpi_4_defconfig and rpi_arm64_defconfig I think.

I checked rpi_arm64_defconfig history. it's unified config for RPi3/RPI4.
As i know, RPi3 doesn't support SDMA mode. So i don't have a plan to apply rpi_arm64_defconfig.
(If i understood wrong, let me know,plz.)

I have tested SDMA mode With rpi_4_defconfig / rpi_4_32b_defconfig.
Test Environment
- Target : RPI4 (1G/2G/4G) target
- config : rpi_4_defconfig / rpi_4_32b_defconfig

Read/write some files from Sd-card.
Read/write performance is increased than before.

I will resend with rpi_4_defconfig, except rpi_arm64_defconfig.

Best Regards,
Jaehoon Chung

> 
> Regards,
> Matthias
> 
>>  CONFIG_MMC_SDHCI_BCM2835=y
>>  CONFIG_DM_ETH=y
>>  CONFIG_BCMGENET=y
>>
> 
>