Re: post 2.6.34 bug: new code enabled by default

From: Mauro Carvalho Chehab
Date: Wed May 26 2010 - 00:12:40 EST


Stefan Richter wrote:
> $ make oldconfig
> ...
> * Multimedia drivers
> *
> Compile Remote Controller keymap modules (RC_MAP) [M/n/?] (NEW) n
> Enable IR raw decoder for the NEC protocol (IR_NEC_DECODER) [M/n/?] (NEW) n
> Enable IR raw decoder for the RC-5 protocol (IR_RC5_DECODER) [M/n/?] (NEW) n
> Enable IR raw decoder for the RC6 protocol (IR_RC6_DECODER) [M/n/?] (NEW) n
> Enable IR raw decoder for the JVC protocol (IR_JVC_DECODER) [M/n/?] (NEW) n
> Enable IR raw decoder for the Sony protocol (IR_SONY_DECODER) [M/n/?] (NEW) n
>
> Please leave the default of new options at N.
>
> (Unless this were a special case of new options that replaced older
> options and need to be migrated to 'on' per default in make oldconfig.
> I think this is not the case here.)

This is the case here. Before the RC subsystem, the decoding for NEC and RC-5
were done inside ir-core (at ir-functions). Also, all the keymap entries (RC_MAP)
were compiled in-kernel.

The intention is to move the RC_MAP keytables to userspace, by default, but there
are still some work to be done at the userspace application before we can do it.

So, without RC_MAP, IR_NEC_DECODER and IR_RC5_DECODER, the input driver will be
compiled, but the IR support may not actually work, if the board needs IR raw
support.

That's said, the support for RC-6, JVC and Sony protocols (IR_RC6_DECODER,
IR_JVC_DECODER and IR_SONY_DECODER) are new. Yet, even on this case, it may make
sense to keep the default to Y, or to add a logic to auto-select the IR decoder
protocols that are needed in order to support the bundled IR found at the compiled
drivers.

--

Cheers,
Mauro
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