[PATCH v2] video: simplefb: add mode parsing function

Alexandre Courbot gnurou at gmail.com
Tue May 28 00:57:51 EDT 2013


On Tue, May 28, 2013 at 1:13 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 05/26/2013 09:53 PM, Alexandre Courbot wrote:
>> The naming scheme of simplefb's mode is precise enough to allow building
>> the mode structure from it instead of using a static list of modes. This
>> patch introduces a function that does this. In case exotic modes that
>> cannot be represented from their name alone are needed, the static list
>> of modes is still available as a backup.
>>
>> It also changes the order in which colors are declared from MSB first to
>> the more standard LSB first.
>>
>> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
>> ---
>> Changes from v1:
>> - amended documentation following Stephen's suggestion
>> - allow parsing of bitfields larger than 9 bits
>> - made it clear that the parsing order of bits is changed with respect
>>   to the original patch
>>
>> Andrew, since this patch introduces a (small) change in the DT bindings,
>> could we try to merge it during the -rc cycle so we don't have to come
>> with a more complex solution in the future?
>
> So, I think we shouldn't change the DT binding at all now. The original
> driver is now merged for 3.10, and I think it's far too late to take
> code that implements new features for 3.10. This means that we couldn't
> merge this patch until 3.11. However, by then, we shouldn't be changing
> the DT binding in incompatible ways. Olof has already published some
> U-Boot binaries that use the current binding, and on IRC indicated he'd
> prefer not to change the binding because of that.
>
> As such, we should either:
>
> a) Just add new entries into the format array that already exists in the
> driver. Given David's response, this might be simplest.
>
> b) Extend the DT binding in a 100% backwards-compatible way, which would
> mean defaulting the bit-order to match the existing 1 format, and adding
> a new Boolean property to indicate that the format string is specified
> in the other order.

a) is definitely simpler, so let's do that and drop this patch. Sorry
about the noise.

Alex.



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