Re: [PATCH 18/18] spi: (RFC, don't apply) report OF style modalias when probing using DT

From: Javier Martinez Canillas
Date: Thu Aug 20 2015 - 19:47:10 EST


Hello Mark,

On 08/21/2015 01:25 AM, Mark Brown wrote:
> On Thu, Aug 20, 2015 at 11:45:09PM +0200, Javier Martinez Canillas wrote:
>> On 08/20/2015 11:08 PM, Brian Norris wrote:
>
>>>> This is tagged as something that can't be applied but you've not
>>>> explained why it can't be applied or what comments might be useful :(
>
>> As Brian pointed out it was in the cover letter so I thought it would
>> just be duplicated information. But you are right, I should had added
>> a brief note as well just to make the patch self contained.
>
> Right, a big part of what I was looking for was something about why this
> is an incompatible change in the changelog so that once it gets applied
> someone with out of tree code which gets broken can see what happens.

Yes, you are absolutely right. When I finally post this as a proper
patch I'll make sure to have a big NOTE so people can track module
autoload issues for OF drivers down to this commit.

> Plus...
>
>>> I believe that's mostly addressed in the cover letter [1].
>
>>> Patch #18 changes the logic of spi_uevent() to report an OF modalias
>>> if the device was registered using OF. But this patch is included in
>>> the series only as an RFC for illustration purposes since changing
>>> that without first applying all the other patches in this series, will
>>> break module autoloading for the drivers of devices registered using
>>> OF but that lacks an of_match_table. I'll repost patch #18 once all
>>> the patches in this series have landed.
>
>>> IOW, it's labeled as such mostly for safety, since it has quite a few
>>> distributed dependencies.
>
> Are there really only 17 drivers that are missing an explict of_table?
> That seems like a low number.
>

In fact the 17 patches are the combination of the SPI drivers that:

a) Have a .id_table but not a MODULE_DEVICE_TABLE(spi,...)
b) Have a .of_match_table but no a MODULE_DEVICE_TABLE(of,...)
c) Don't have a .of_match_table but have a DT binding document

Maybe there are more SPI drivers out there that only have a .id_table
and don't have a .of_match_table nor a DT binding doc. But in that case
there isn't too much I can do since I've no information that these are
drivers are actually used in systems booted with OF.

Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
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