On Apr 8, 2011, at 11:22 AM, Lawrence Rust wrote:
> On Fri, 2011-04-08 at 10:41 -0400, Jarod Wilson wrote:
>> On Apr 8, 2011, at 8:50 AM, Lawrence Rust wrote:
>>
>>> This patch restores remote control input for cx2388x based boards on
>>> Linux kernels >= 2.6.38.
>>>
>>> After upgrading from Linux 2.6.37 to 2.6.38 I found that the remote
>>> control input of my Hauppauge Nova-S plus was no longer functioning.
>>> I posted a question on this newsgroup and Mauro Carvalho Chehab gave
>>> some helpful pointers as to the likely cause.
>>>
>>> Turns out that there are 2 problems:
>> ...
>>> 2. The RC5 decoder appends the system code to the scancode and passes
>>> the combination to rc_keydown(). Unfortunately, the combined value is
>>> then forwarded to input_event() which then fails to recognise a valid
>>> scancode and hence no input events are generated.
>>
>> Just to clarify on this one, you're missing a step. We get the scancode,
>> and its passed to rc_keydown. rc_keydown then looks for a match in the
>> loaded keytable, then passes the *keycode* that matches the scancode
>> along to input_event. If you fix the keytable to contain system and
>> command, everything should work just fine again. Throwing away data is
>> a no-no though -- take a look at recent changes to ir-kdb-i2c, which
>> actually just recently made it start *including* system. :)
>
> Don't shoot the messenger.
Wasn't my intention. I was simply trying to explain why your "fix"
isn't correct.
> I'm just reporting what I had to do to fix a clumsy hack by someone 6
> months ago who didn't test their changes. This patch _restores_ the
> operation of a subsystem broken by those changes
>
> Perhaps those responsible for commit
> 2997137be8eba5bf9c07a24d5fda1f4225f9ca7d:
>
> Signed-off-by: David Härdeman <david@xxxxxxxxxxx>
> Acked-by: Jarod Wilson <jarod@xxxxxxxxxx>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
>
> should fix the keytable. In the meantime (next year) I'll be using this
> patch.
The entire commit message:
[media] ir-core: convert drivers/media/video/cx88 to ir-core
This patch converts the cx88 driver (for sampling hw) to use the
decoders provided by ir-core instead of the separate ones provided
by ir-functions (and gets rid of those).
The value for MO_DDS_IO had a comment saying it corresponded to
a 4kHz samplerate. That comment was unfortunately misleading. The
actual samplerate was something like 3250Hz.
The current value has been derived by analyzing the elapsed time
between interrupts for different values (knowing that each interrupt
corresponds to 32 samples).
Thanks to Mariusz Bialonczyk <manio@xxxxxxxxxx> for testing my patches
(about one a day for two weeks!) on actual hardware.
Please note the part about how it *was* tested. And this certainly
was not a "clumsy hack", I'd actually call it a fairly skilled bit
of code de-duplication by David. Anyway...
The problem is that there isn't a "the keytable". There are many
many keytables. And a lot of different hardware. Testing all possible
combinations of hardware (both receiver side and remote side) is
next to impossible. We do what we can. Its unfortunate that your
hardware regressed in functionality. It happens, but it *can* be
fixed. The fix you provided just wasn't correct. The correct fix is
trivially updating drivers/media/rc/keymaps/<insert-your-keymap-here>.
--
Jarod Wilson
jarod@xxxxxxxxxxxx
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