[Linux-fbdev-users] nvidiafb: flickering LCD

[Ali G. R. <ali...@gm...>]

Hi,

I've got a GeForce 7100 GS and a 17-inch L1730S LG monitor.  The native
resolution of the LCD is 1280x1024.  The problem is the framebuffer
works perfectly when it uses 8-bit color depth but it flickers for 16,
24 and 32-bit color depths (in 32-bit it flickers much worse than in
16-bit).

fbset reports the same mode in all cases:

  mode "1280x1024-60"
      # D: 108.003 MHz, H: 63.983 kHz, V: 60.021 Hz
      geometry 1280 1024 1280 25990 16
      timings 9259 248 48 38 1 112 3
      hsync high
      vsync high
      accel true
      rgba 5/11,6/5,5/0,0/0
  endmode

The same happens for "1280x1024-75"; ie. bpp=8 works and for other
values, the screen flickers while fbset reports the same mode for all
values of bpp.

I use 2.6.31> kernel and pass video=nvidia:1280x1024-16@60 to the
kernel; I tried other values of refresh rate like 50, 65, 70 and 75 with
no luck.  Also I tried inserting M and R characters before the dash but
again it didn't do anything positive.

Xorg works with no problem (with any bpp value):

  ...
  (II) NV(0): Supported detailed timing:
  (II) NV(0): clock: 108.0 MHz   Image Size:  338 x 270 mm
  (II) NV(0): h_active: 1280  h_sync: 1328  h_sync_end 1440 h_blank_end 1688 h_border: 0
  (II) NV(0): v_active: 1024  v_sync: 1025  v_sync_end 1028 v_blanking: 1066 v_border: 0
  (II) NV(0): Ranges: V min: 56 V max: 75 Hz, H min: 30 H max: 83 kHz, PixClock max 140 MHz
  (II) NV(0): Monitor name: L1730S
  ...

The selected mode is the same as the one selected by the kernel for the
framebuffer.

Any idea what's wrong?  What is the relation between bpp and display
timings?  Any other confs that might work?

Thanks,
Ali