Re: [PATCH v2 0/4] Patches to allow consistent mmc / mmcblk numbering w/ device tree

From: Peter Hurley
Date: Fri Apr 29 2016 - 19:58:24 EST


On 04/29/2016 04:01 PM, Doug Anderson wrote:
> * serial allows numbering devices by alias.

Which is in fact a total nightmare.

While stable device order is mandatory in serial because of
console command line parameters and existing userspace expectations,
it is the number one barrier to providing a shared ttyS namespace
for mixed uart platforms.

Stable device order has a very real (and often unforeseen) maintenance
burden.

For example, I noticed these patches are strictly for DT.
I'm assuming that's because guaranteeing stable device order for
mmc in general is more difficult; eg., by performing minimal scan
serially and more expensive portion of the probe async.

Regards,
Peter Hurley