[mythtv-users] LIRC kernel strangeness with more than four devices

[Jarod Wilson]

On Apr 12, 2011, at 2:01 PM, Ramin K wrote:

> On 4/12/2011 9:23 AM, Jarod Wilson wrote:
>> On Apr 11, 2011, at 8:18 PM, Ramin K wrote:
>> 
>>> 	I had been playing around with four HDPVRs attached to single machine
>>> and all was well. Once I attached the fifth the kernel started
>>> complaining loudly and a sixth took the machine completely down.
>>> 	After I bit of tail chasing I tracked it down to
>>> lirc/drivers/lirc_dev/lirc_dev.h which sets
>>> 
>>> #define MAX_IRCTL_DEVICES 4
>>> 
>>> 	Doing a bit of research it appears this is an arbitrary limit since it
>>> used to be 2 and it was simple to raise it to 4.
>> 
>> Yeah, looks like it could be trivially increased, all it would do is waste
>> a tiny bit of memory. That area of code could actually use some further
>> love to make the irctl storage dynamically expand as needed.
>> 
> 
> 	Thanks for looking at the code. It appeared that changing it to 8 or 12 
> should be simple, but having a second opinion makes me feel better.
> 	I was hesitant to push upstream for a max of 8 or 12 since I'm 
> definitely not the average user. A dynamic expand sounds like a much 
> better and longer term solution.

I've pushed a change to bump to 8 as of kernel 3.0, was pulled into linus'
tree last week. Looked briefly at dynamic, was going to be more work than
I had time or desire for, but this change was done in a way that doesn't
actually use up much more memory, since the cdev is now dynamically
allocated, and only irctls remain as a static global.

Commit 8de111e27688798623b9e9062235bb0cac29f599 in linus' tree.

-- 
Jarod Wilson
jarod at wilsonet.com