This is patch against latest n770 2.6.16 kernel. It fixes display update in YUV420 mode. Default unpatched kernel just
hangs and reboots or messes up display.

patch details:
- added waiting for YYC converter for YUV modes (similar code is blizzard.c in n800 kernel), this is not strictly needed
and seems to work without it, but is suggested by S1D13742 specifications
- width not harcoded to 800 but read from panel data (similar code is in blizzard.c for n800)
- removed bpp variable as offset computation does not depend on current color mode, it depends only on real framebuffer
layout
- align x,y,h,w for YUV modes otherwise unaligned update can hang the device (similar code is in blizzard.c for n800,
HW limitation is mentioned in S1D13742 specs)
- adjust the number of transfer elements per line for YUV420 (12bpp) format, current code sends too much data and hw
is confused (similar code is in blizzard.c for n800 kernel)

Date: 2007-06-29 20:49
Sender: Álvaro J. Iradier Muro

Thanks, tried but the problem didn't fix, so it looks it's not
realted.

Date: 2007-06-29 20:26
Sender: Frantisek Dufka

"When trying to play a youtube video in hacker edition,
the screen is corrupted. Is this fix related to it, or is it
a completely different problem?"

Not sure. It is unlikely but possible. YUV420 mode was probably
never used on N770 in IT2006 and most of media framework in HE
was copied from IT2006 (older kernel, dsp codecs,..) but it is
true that firmware based on N800 code could use this mode as
on N800 it works and it could be even preferred mode due to video
bandwidth restrictions of N800.

Anyway, you can verify it by flashing kernel with this patch.
See
http://www.internettablettalk.com/forums/showthread.php?p=50004#p
ost50004

Date: 2007-06-29 18:44
Sender: Álvaro J. Iradier Muro

When trying to play a youtube video in hacker edition, the screen
is corrupted. Is this fix related to it, or is it a completely
different problem?

Date: 2007-05-22 12:50
Sender: Frantisek Dufka

When checking S1D13742 specs again the YYC converter idle bit
must be checked only for YUV420, it may be not needed for YUV422.
Page 72: "This bit will go low once the YYC is idle. At
this point, a new window can be written.
When doing back-to-back window writes with a different dimension
or format, and the
first window is YUV 4:2:0, before starting to write the second
window, make sure this bit
is low."