From mboxrd@z Thu Jan 1 00:00:00 1970 From: David =?iso-8859-1?Q?H=E4rdeman?= Subject: Re: [PATCH 3/4] ir-core: move decoding state to ir_raw_event_ctrl Date: Sun, 13 Jun 2010 22:29:45 +0200 Message-ID: <20100613202945.GA5883@hardeman.nu> References: <20100424211411.11570.2189.stgit@localhost.localdomain> <4BDF2B45.9060806@redhat.com> <20100607190003.GC19390@hardeman.nu> <20100607201530.GG16638@redhat.com> <20100608175017.GC5181@hardeman.nu> <20100609132908.GM16638@redhat.com> <20100609175621.GA19620@hardeman.nu> <20100609181506.GO16638@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from 1-1-12-13a.han.sth.bostream.se ([82.182.30.168]:46122 "EHLO palpatine.hardeman.nu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754766Ab0FMU3t (ORCPT ); Sun, 13 Jun 2010 16:29:49 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Jarod Wilson Cc: Jarod Wilson , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-input@vger.kernel.org On Wed, Jun 09, 2010 at 09:25:44PM -0400, Jarod Wilson wrote: > On Wed, Jun 9, 2010 at 2:15 PM, Jarod Wilson wrote= : > > On Wed, Jun 09, 2010 at 07:56:21PM +0200, David H=E4rdeman wrote: > >> On Wed, Jun 09, 2010 at 09:29:08AM -0400, Jarod Wilson wrote: > ... > >> > So this definitely negatively impacts my ir-core-to-lirc_dev > >> > (ir-lirc-codec.c) bridge driver, as it was doing the lirc_dev de= vice > >> > registration work in its register function. However, if (after y= our > >> > patchset) we add a new pair of callbacks replacing raw_register = and > >> > raw_unregister, which are optional, that work could be done ther= e instead, > >> > so I don't think this is an insurmountable obstacle for the lirc= bits. > >> > >> While I'm not sure exactly what callbacks you're suggesting, > > > > Essentially: > > > > .setup_other_crap > > .tear_down_other_crap > > > > ...which in the ir-lirc-codec case, register ir-lirc-codec for a sp= ecific > > hardware receiver as an lirc_dev client, and conversely, tear it do= wn. > > > >> it still > >> sounds like the callbacks would have the exact same problems that = the > >> current code has (i.e. the decoder will be blissfully unaware of > >> hardware which exists before the decoder is loaded). Right? > > > > In my head, this was going to work out, but you're correct, I still= have > > the exact same problem -- its not in ir_raw_handler_list yet when > > ir_raw_event_register runs, and thus the callback never fires, so l= irc_dev > > never actually gets wired up to ir-lirc-codec. It now knows about t= he lirc > > decoder, but its completely useless. Narf. >=20 > And now I have it working atop your patches. Its a bit of a nasty-ish > hack, at least for the lirc case, but its working, even in the case > where the decoder drivers aren't actually loaded until after the > device driver. I've added one extra param to each protocol-specific > struct in ir-core-priv.h (bool initialized) and hooked into the > protocol-specific decode functions to both determine whether a > protocol should be enabled or disabled by default, and to run any > additionally required initialization (such as in the ir-lirc-codec > case). >=20 > So initially, mceusb comes up with all decoders enabled. Then when ir > comes in, every protocol-specific decoder fires. Each of them check > for whether or not they've been fully initialized, and if not, we > check the loaded keymap, and if it doesn't match, we disable that > decoder (bringing back the "disable protocol handlers we don't need" > functionality that disappeared w/this patchset). In the lirc case, we > actually do all the work needed to wire up the connection over to > lirc_dev. >=20 > This works perfectly fine for all the in-kernel decoders, but has one > minor shortcoming for ir-lirc-codec, in that /dev/lirc0 won't actuall= y > exist until the first incoming ir signal is seen. lircd can handle > this case just fine, it'll wait for /dev/lirc0 to show up, but it > doesn't come up fast enough to catch and decode the very first > incoming ir signal. Subsequent ones work perfectly fine though. This > need to initialize the link via incoming ir is a bit problematic if > you're using a device for transmit-only (e.g., and mceusb device > hooked to a mythtv backend in the closet or something), as there woul= d > be a strong possibility of /dev/lirc0 never getting hooked up. I can > think of a few workarounds, but none are particularly clean and/or > automagic. >=20 > Not sure how palatable it is, but here it is: I think it sounds pretty awful :) I have another suggestion, let's keep the client register/unregister=20 callbacks for decoders (but add a comment that they're only used for=20 lirc). Then teach drivers/media/IR/ir-raw-event.c to keep track of the=20 raw clients so that it can pass all pre-existing clients to newly added= =20 decoders. I'll post two patches (compile tested only) in a few seconds to show=20 what I mean. --=20 David H=E4rdeman -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html