• Status Closed
  • Percent Complete
  • Task Type Patches
  • Category LCD
  • Assigned To No-one
  • Operating System Sansa e200
  • Severity Low
  • Priority Very Low
  • Reported Version Daily build (which?)
  • Due in Version Undecided
  • Due Date Undecided
  • Votes 2
  • Private
Attached to Project: Rockbox
Opened by JL - 2007-09-01
Last edited by MikeS - 2007-09-05

FS#7692 - LCD garbled top two lines

This fixes the problem of two top lines garbled in Rockbox and original firmware when loaded from RB bootloader.
You will need to rebuild Bootloader and main Rockbox. remove other workaround patches.
For those that care what it does.It Changes LCD driver from having one front porch raster-row to having two. The docs for the chip reads
FP3-0/BP3-0: Make settings for blank periods (the front and back porches), which are placed at the
beginning and end of the display. FP3-0 and BP3-0 bits specify the number of raster-rows for the front and back porch respectively. When making this setting, make sure:

   BP + FP = <16 raster-rows
   FP >= 2 raster-rows
   BP >= 2 raster-rows
Closed by  MikeS
2007-09-05 08:34
Reason for closing:  Accepted
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407

Does the job.

This does not seem to be a patch file? how is one to install this?

JL commented on 2007-09-04 12:03

I made the patch following the directions at If some one could tell me what I may have done wrong I will fix it.
in the mean time you can change the line in /rockbox/firmware/target/arm/sandisk/sansa-e200/lcd-e200.c
that reads
lcd_write_reg(R_DISP_CONTROL2, 0×0102);
lcd_write_reg(R_DISP_CONTROL2, 0×0202);
That will change the front porch from one to two lines.
Having only one or zero lines for the front porch is described as Setting disabled.
in the lit for the chip.

FP3 FP2 FP1 FP0 Number of lines for the Front Porch
BP3 BP2 BP1 BP0 Number of lines for the Back Porch
0 0 0 0 Setting disabled
0 0 0 1 Setting disabled
0 0 1 0 2

jrbil commented on 2007-09-05 01:10

Works for me. There was still a little garbage when the screen was cleared after the bootloader started rockbox (minor and cosmetic). Changing one line to copy 220 lines instead of 222 fixed that. I’ve attached the new patch file here. Looks like a real fix. Just need someone with an early model to test it.

   patch (1.1 KiB)
JL commented on 2007-09-05 04:12

I like your patch. Looks nicer when it comes up.
I have good news I tried both patches on my new 1.1Ver board and on my brothers old 1.0Ver board and both work perfect.
Both the new and old Sansa’s were the 8 Gig models.
Hope they will add this to the normal build. I don’t see any down side.


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