Hi Mauro, On Wed, 31 Mar 2010 14:46:37 -0300, Mauro Carvalho Chehab wrote: > Hi Jean, > > Jean Delvare wrote: > > Hi Andrzej, > > > > Last year, you submitted a fix for the cx88 remote control not behaving > > properly on some cards. The fix works fine for me and lets me use my > > remote control, and I am very grateful for this. > > > > However, I have noticed (using powertop) that the cx88 driver is waking > > up the kernel 1250 times per second to handle the remote control. I > > understand that it is needed for proper operation when the remote > > control is in use. What I do not understand is why it still happens > > when nobody uses the remote control. Even when no application has the > > event device node opened, polling still happens. > > > > Can't we have the cx88 driver poll the remote control only when the > > device node is opened? I believe this would save some power by allowing > > the CPU to stay in higher C states. > > The IR can be used even when nobody is opening the /dev/video device, as > it is an input device that can be used to control other things, including > the start of the video application. > > That's said, it makes sense to only enable the polling when the /dev/input/event > device is opened. Sorry for not being clear originally; this is exactly what I meant. > Btw, the same polling logic is also present on bttv and saa7134 drivers. > > As I'm doing a large IR rework, with the addition of the IR core subsystem, > and the patch for handing the open/close is very simple, I've already wrote > a patch for saa7134, on my IR tree: > http://git.linuxtv.org/mchehab/ir.git?a=commitdiff;h=2b1d3acdb48266f05b82923b8db06e6c7ada0c72 > > The change itself is very simple, although I've added some additional checks > to avoid the risk of having an IRQ while IR is disabled. Looks very good, nice to see someone is already working on the problem. > I have one cx88 board on my IR test machine (although I need to find the IR sensor for the > board I'm using there). If I find one that works, I'll try later to write a similar > code to cx88. Thanks, -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
