Re: [PATCH 1/2] s5p-mfc: Update mfc-v6 firmware

[Tomasz Figa <t.figa@samsung.com>]

Hi Kamil, Arun,

On 16.05.2014 12:09, Kamil Debski wrote:
> Hi,
> 
> ----Original Message-----
>> From: arunkk.samsung@gmail.com [mailto:arunkk.samsung@gmail.com] On
>> Behalf Of Arun Kumar K
>> Sent: Friday, May 16, 2014 12:00 PM
>>
>> Hi Kamil,
>>
>> On Fri, May 16, 2014 at 3:24 PM, Kamil Debski <k.debski@samsung.com>
>> wrote:
>>> Hi Arun,
>>>
>>> I asked you to put old and new v6 firmware in separate files.
>>
>> But wont that require a different filename other than s5p-mfc-v6.fw?
> 
> Yes.
> 
>> But the driver still expects the same file name.
>> Can I put the new filename as s5p-mfc-v6-v2.fw and mention in the
>> README that the file has to be renamed to s5p-mfc-v6.fw to be used?
> 
> I think this is the way to go, because the new driver (with the patch)
> will work with old firmware, while old driver (without the patch) will
> not work with the new firmware.
> 
>>
>>> You should also mention in the commit message that this new firmware
>>> will not work with the s5p-mfc driver without the patch you recently
>>> submitted to linux-media mailing list. Please also add a link to the
>>> thread with the necessary patch.
>>
>> Ok will do that.
>>
>>>
>>> In addition to the above I think a readme/description file should be
>>> added to the s5p-mfc folder. The issue of firmware for v6 should be
>>> explained, so that no one is surprised that something does not work.
>>>

May I suggest a little different solution?

Since to not break compatibility, support for both firmware versions is
needed in the driver anyway, why not simply make the new, incompatible
firmware always use a different filename.

Then let the driver try to load the new one first and if it fails then
load the old one? This would also let you get rid of that version check
by hardcoded date, as you would know which firmware type was found.

Best regards,
Tomasz