diff options
| -rw-r--r-- | drivers/video/cirrusfb.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c index 65a1831ddd0..15e2e6bfcbf 100644 --- a/drivers/video/cirrusfb.c +++ b/drivers/video/cirrusfb.c @@ -470,10 +470,25 @@ static int cirrusfb_check_pixclock(const struct fb_var_screeninfo *var, /* If the frequency is greater than we can support, we might be able * to use multiplexing for the video mode */ if (freq > maxclock) { + dev_err(info->device, + "Frequency greater than maxclock (%ld kHz)\n", + maxclock); + return -EINVAL; + } + /* + * Additional constraint: 8bpp uses DAC clock doubling to allow maximum + * pixel clock + */ + if (var->bits_per_pixel == 8) { switch (cinfo->btype) { case BT_ALPINE: + case BT_PICASSO4: + if (freq > 85500) + cinfo->multiplexing = 1; + break; case BT_GD5480: - cinfo->multiplexing = 1; + if (freq > 135100) + cinfo->multiplexing = 1; break; default: @@ -815,6 +830,8 @@ static int cirrusfb_set_par_foo(struct fb_info *info) freq = PICOS2KHZ(var->pixclock); if (cinfo->btype == BT_ALPINE && var->bits_per_pixel == 24) freq *= 3; + if (cinfo->multiplexing) + freq /= 2; bestclock(freq, &nom, &den, &div); |