lkml.org 
[lkml]   [2017]   [Aug]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 1/3] firmware: of: populate /firmware/ node during init
On Fri, Aug 11, 2017 at 9:37 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Fri, Aug 11, 2017 at 3:30 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>> Since "/firmware" does not have its own "compatible" property as it's
>> just collection of nodes representing firmware interface, it's sub-nodes
>> are not populated during system initialization.
>>
>> Currently different firmware drivers search the /firmware/ node and
>> populate the sub-node devices selectively. Instead we can populate
>> the /firmware/ node during init to avoid more drivers continuing to
>> populate the devices selectively.
>>
>> This patch adds initcall to achieve the same.
>
> Hmm, I'm a bit skeptical whether representing anything under /firmware
> as a platform device is a good idea. Having a more structured way to
> probe those seems like a good idea, but maybe a different subsystem
> would be more appropriate.
>
> I do realize that a 'platform_device' has become a rather generic abstraction
> for almost anything, but at some point we might want to draw the line
> of what is a platform_device.

I guess the question how are they different? Most of what's under
drivers/firmware/ are platform drivers. I think they are mostly either
smc calls or mailbox interfaces. Would there be any advantage to
creating an smc bus or mailbox bus?

It's easier to convert from a platform driver to some new bus_type
than convert from a non-driver if we decide to do that later.

The other approach would be to do a whitelist of compatibles. That's
what's being done for /reserved-memory (currently there's one
(ramoops) and a 2nd is being added).

Rob

\
 
 \ /
  Last update: 2017-08-11 17:06    [W:4.955 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site