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Diffstat (limited to 'drivers/video/mbx/mbxfb.c')
| -rw-r--r-- | drivers/video/mbx/mbxfb.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/video/mbx/mbxfb.c b/drivers/video/mbx/mbxfb.c index 6849ab75d40..cfc6bf3615b 100644 --- a/drivers/video/mbx/mbxfb.c +++ b/drivers/video/mbx/mbxfb.c @@ -118,8 +118,19 @@ static unsigned int mbxfb_get_pixclock(unsigned int pixclock_ps, /* convert pixclock to KHz */ pixclock = PICOS2KHZ(pixclock_ps); + /* PLL output freq = (ref_clk * M) / (N * 2^P) + * + * M: 1 to 63 + * N: 1 to 7 + * P: 0 to 7 + */ + + /* RAPH: When N==1, the resulting pixel clock appears to + * get divided by 2. Preventing N=1 by starting the following + * loop at 2 prevents this. Is this a bug with my chip + * revision or something I dont understand? */ for (m = 1; m < 64; m++) { - for (n = 1; n < 8; n++) { + for (n = 2; n < 8; n++) { for (p = 0; p < 8; p++) { clk = (ref_clk * m) / (n * (1 << p)); err = (clk > pixclock) ? (clk - pixclock) : |