Firmware to support LTS kernels

[Tim Gardner]

On 07/15/2013 04:57 AM, Andy Whitcroft wrote:
> On Fri, Jul 12, 2013 at 08:48:54AM -0600, Tim Gardner wrote:
>> With the advent of LTS kernels, maintenance of the linux-firmware
>> package in Precise is becoming a bit of a problem. Due to SRU policy,
>> updates to firmware files has been difficult. It has recently become a
>> bit easier to _add_ new firmware files, but suffice it to say, Precise
>> linux-firmware has diverged significantly from upstream.
>>
>> My original plan had been to carry any new or updated firmware files
>> required by a particular LTS kernel in the kernel package itself. That
>> has the advantage of being independent of the Precise linux-firmware
>> package. However, there are 2 disadvantages to that scheme:
>>
>> 1) If you have multiple LTS kernels installed, then you'll have multiple
>> copies of the updated firmware also installed. Given the size of the
>> kernel itself, the relatively small firmware files might not have much
>> of an impact.
>>
>> 2) Each subsequent LTS kernel package has to carry the cumulative
>> firmware updates from the previous LTS kernels, e.g., the Saucy LTS
>> kernel must carry all additions from Quantal and Raring.
>>
>> I received some objections to this approach wherein it was suggested
>> that I just add new files to Precise linux-firmware to support LTS
>> kernels. The issues I have with that are:
>>
>> 1) Users that never install an LTS kernel continue to accrue new (and
>> useless to them) firmware files.
>> 2) Updates to existing files are sometimes difficult to verify.
>> 3) Catching up to upstream is gonna require a massive SRU effort.
>>
>> If we're gonna continue to update Precise linux-firmware to support LTS
>> kernels, then I guess I'd like to reset the content of the Precise
>> package to be that of Saucy (which is current with upstream). Saucy is
>> mostly a superset of Precise, but there _have_ been a few modifications
>> to existing firmware files.
>>
>> Thoughts ? Things are only going to get worse with the 14.04 kernel in
>> Precise.
> 
> Could we take a middle ground and backport the firmware package as well,
> as in have a single linux-firmware-lts which has the accumulated extras
> and depends on the main one in precise, and is further depended on by
> the lts kernels.
> 
> We might be able to automate that, ie literally take the saucy once, and
> the precise one and run something to make a delta package for precise.
> 
> -apw
> 

I thought about that approach, but it doesn't seem very elegant since it
would have to have a 'Replaces:' in order to avoid file conflicts with
the linux-firmware package from Precise. If we installed into a
completely different directory, then we have to teach udev about the
location of the new firmware (which is not impossible).

rtg
-- 
Tim Gardner tim.gardner at canonical.com