Re: [PATCH 2/4] mmc: bcm2835: Add new driver for the internal SD controller.

From: Ulf Hansson
Date: Mon Jan 30 2017 - 03:22:41 EST

On 27 January 2017 at 17:04, Stefan Wahren <stefan.wahren@xxxxxxxx> wrote:
> Am 27.01.2017 um 16:27 schrieb Ulf Hansson:
>> On 27 January 2017 at 12:36, Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote:
>>> From: Eric Anholt <eric@xxxxxxxxxx>
>>> The 2835 has two SD controllers: The Arasan SDHCI controller (supported
>>> by the iproc driver) and a custom SD controller. This patch adds a
>>> driver for the custom SD controller.
>>> The custom controller runs faster, and driving the sdcard with the
>>> custom controller also allows to drive the rpi3 wifi with the iproc
>>> driver.
>> I don't understand this relationship. Is this somewhat configurable in runtime?
> The configuration is done by devicetree via pin muxing. AFAIK both SD
> controller are available on the same pins (2 pin groups = pin 22 to 27 +
> pin 48 to 53). So it's possible to use both SD controllers at the same
> time with different pin groups. This is necessary to use Wifi via SDIO
> on the RPi 3 while the other controller handles SD card with the rootfs.
>> Is the WIFI module a removable SDIO card?
> No
>> So you can decide which
>> controller that is best suited to use?
> Yes, but it requires also both drivers.

Okay, thanks for clarifying - I will go on with the review.

If a re-spin of the series is needed, please make sure to update the
coverletter with some information from above, so I don't get confused
again. :-)

Kind regards