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Rockbox mail archiveSubject: Re: development questionsRe: development questions
From: Linus Nielsen Feltzing <linus_at_haxx.se>
Date: Mon, 17 Jan 2005 08:53:14 +0100 Ray Lambert wrote: > I'm not sure what you mean by "off-screen" icons. I had a hard time finding a good name for it. :-) > Are you saying there are two different display areas on these > devices; one that uses fonts and one which doesn't, or something like > that? It's a two-line text display surrounded by fixed icons. The font can't be changed, but the LCD can redefine up to 8 custom characters. We use that to simulate a latin-8 character set. > In any case, I guess it sounds like there's nothing I can do. :( Exactly. > Since my post, I've found a new way to do from mpeg.c which was > pretty easy and seems to be more accurate. I put the check in > playback_tick() (since that's where id3->elapsed gets updated). This > seems to work very well but I'm not sure if it's a good design > decision to put my code there. That's where I would put it. > The main question is whether it's safe. playback_tick() is called > from a timer interrupt. Everything in my code seems to be safe to > touch in an interrupt (atomic and read-only); the only question is > whether the calls back to mpeg.c are safe. They all end-up doing a > queue_post(), which is safe so long as the queuing operation is safe. Yup. The queue_post() function is interrupt safe, and is intended to be called from interrupts. > There's also a question of using too much CPU in the interrupt. But > there's really only a few integer comparisons taking place and the > queue_post() call. So I think that's okay. I haven't noticed any > problems in my testing so far. I think it sounds perfectly OK. Bring on the patch! :-) Linus _______________________________________________ http://cool.haxx.se/mailman/listinfo/rockbox Received on 2005-01-17 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |