Re: [PATCH 1/2] mmc: block: mmcblkN: use slot index instead of dynamic name index

[Chris Ball <cjb@laptop.org>]

Hi,

On Mon, Aug 06 2012, Dirk Behme wrote:
> On embedded devices, often there is a combination of removable mmc
> devices (e.g. MMC/SD cards) and hard wired ones (e.g. eMMC).
> Depending on the hardware configuration, the 'mmcblkN' node might
> change if the removable device is available or not at boot time.
>
> E.g. if the removable device is attached at boot time, it might
> become mmxblk0. And the hard wired one mmcblk1. But if the removable
> device isn't there at boot time, the hard wired one will become
> mmcblk0. This makes it somehow difficult to hard code the root device
> to the non-removable device and boot fast.
>
> This change does simply associate 'N' of 'mmcblkN' with the slot index
> instead of the dynamic name index. The slot index is always the same,
> ensuring that the non-removable mmc device is associated always
> with the same mmcblkN. Independent of the availability of the removable
> one.

I like this change in principle, but doesn't it break boot for everyone
currently using e.g. root=/dev/mmcblk0p1 on slot index 2?  That doesn't
sound like an acceptable regression.

Thanks,

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child