On Mon, Sep 14, 2015 at 07:34:10AM -0700, Eric Nelson wrote: > Thanks Shawn, > > On 09/14/2015 03:00 AM, Sean Young wrote: > > On Fri, Sep 11, 2015 at 07:00:24AM -0700, Eric Nelson wrote: > >> Many decoders require a trailing space (period without IR illumination) > >> to be delivered before completing a decode. > >> > >> Since the gpio-ir-recv driver only delivers events on gpio transitions, > >> a single IR symbol (caused by a quick touch on an IR remote) will not > >> be properly decoded without the use of a timer to flush the tail end > >> state of the IR receiver. > > > > This is a problem other IR drivers suffer from too. It might be better > > to send a IR timeout event like st_rc_send_lirc_timeout() in st_rc.c, > > with the duration set to what the timeout was. That is what irraw > > timeouts are for; much better than fake transitions. > > > > If I'm understanding this correctly, this would require modification > of each decoder to handle what seems to be a special case regarding > the GPIO IR driver (which needs an edge to trigger an interrupt). No, this is not a special case. Many drivers do have extra code to generate some sort of end-of-signal message: redrat3; igorplugusb; st_rc. They don't handle it consistently but this should be fixed. Secondly, the decoders already handle it. A timeout event matches is_timing_event(), so it's processed by the decoders. The duration should be set correctly. > Isn't it better to have the device interface handle this in one place? > >> This patch adds an optional device tree node "flush-ms" which, if > >> present, will use a jiffie-based timer to complete the last pulse > >> stream and allow decode. > > > > A common value for this is 100ms, I'm not sure what use it has to have > > it configurable. It's nice to have it exposed in rc_dev->timeout. > > > > I'm enough of a n00b regarding the details of the various decoders > not to know that... > > I looked through the couple of decoders my customer was using (NEC and > RC6) and came up with a value of 100ms though... > > Implementing this through DT and having the default as 0 (disabled) > provides an interim solution if the choice is made to change each of > the decoders, since I would expect that to take a while and a bunch of > remote control devices for testing. Many other drivers use 100ms just fine and I don't remember ever seeing any bug reports on that. Sean -- 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
