Need kernel timer change to support Leadtek Winfast DTV1000T remote

[falcon15500]

While Bug #151561 addressed the remote control not being detected (it is now detected in Hardy), the kernel timer problem still remains. With the stock kernel timer setting of 250Hz, the remote control has to be pressed repeatedly in order for a keypress to register. This is because of a mismatch between the driver and the kernel timer. The kernel timer needs to be set to 1000Hz for the remote to work reliably. A lot of other distro's default to 1000Hz without ill effect, as it also increases responsiveness of the GUI (apparently).

Can the timer be changed, and an update pushed out? This will prevent a lot of hair pulling for people like me, who have to compile a new customer kernel (and deal with compiling restricted modules) every time the generic kernel is updated.

[laga (laga)]

Hi,

my understand of the 'kernel timer' is that nowadays, most distributions including Ubuntu use 'tickless' kernels. CONFIG_HZ in the config is only used as a fallback.

It'd be better to fix the driver of your remote instead of demanding changes to the kernel. The function of the driver shouldn't depend on the timer setting.

I'm setting this to 'incomplete' for Mythbuntu. Please set to 'new' once a patched driver is available.

[falcon15500 (mike-nine-hells)]

If the CONFIG_HZ is only used as a fallback, why the big problem changing it? Setting the timer to 250 is a default for servers anyway - desktop systems should be set to 1000 (as per the kernel help files). The remote uses the /dev/input system and as I understand it (I admit my understanding is limited) the polling of the IR receiver is directly tied into this kernel parameter. Setting the timer to 250 means a 1 in 4 chance of the keypress being detected.

[laga (laga)]

Hi,

I've just brought it to the attention of some people in #ubuntu-kernel and the answer basically was that the driver is broken if it depends on a specific CONFIG_HZ setting and that it should be fixed.

I assume it's also broken with the new tickless kernels.

[trollord (trollenlord)]

Furthermore, tickless kernels produce huge battery savings for laptops, the default will seriously not go back.

[falcon15500 (mike-nine-hells)]

You can still keep the kernel 'tickless' (ie, CONFIG_NO_HZ = Y) and have the timer set to 1000 - which allows the remote driver to poll every millisecond instead of every 4 milliseconds.

So how do I get someone to look into the driver? The driver is for the cx88 chip...

[falcon15500 (mike-nine-hells)]

I have tried modifiying the driver source to use various other ir->polling values (such as 50ms, 4ms and 2.5ms) for use with a 250hz kernel timer. Unfortunately none of work anywhere near as reliably as 1ms with a 1000hz timer.