Rockbox mail archiveSubject: Re: things to optimize (was Re: Testers wanted: up to 50% greater battery life)
Re: things to optimize (was Re: Testers wanted: up to 50% greater battery life)
From: Daniel Stenberg <daniel_at_haxx.se>
Date: Wed, 30 Jul 2003 16:45:11 +0200 (CEST)
On Wed, 30 Jul 2003, TP Diffenbach wrote:
> Oh dear. Is the update smart enough to not update non-scrolling,
> non-changing lines?
No. lcd_update() writes the full frame buffer to the LCD.
For each 8 y-pixels there are 3 commands written, then there's one byte
written for each pixel column.
8*3 + 8*112 = 920 invokes of lcd_write().
That's also why we added lcd_update_rect() which only updates a given
Certainly we can make a function that doesn't update bytes that haven't
changed, but the major boost tend to be to just to not call lcd_update() more
> The settings code may or may not take longer; the salient point is the
> settings code really isn't needed except for two of the <however many
> settings there are now>. The other salient point is that we swouldn't need
> to do this at all if we could do a clean shutdown that saved settings.
Remember that we only write to the RTC that often. We write to disk when
there's a actual disk activity triggered by other means.
-- Daniel Stenberg -- http://rockbox.haxx.se/ -- http://daniel.haxx.se/Received on 2003-07-30