diff options
| author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2008-07-23 21:31:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:36 -0700 |
| commit | 6280fd4f9c2683a4d2f096320dd74ded4e5106ad (patch) | |
| tree | 2cbb1ccf0c923cf35be3bb6c239cb9b0a43cc8f6 /drivers/video | |
| parent | f330c4b1961d730ef15ac184e4b7f1c25847d0ae (diff) | |
| download | linux-6280fd4f9c2683a4d2f096320dd74ded4e5106ad.tar.gz | |
tridentfb: Blade3D clock fixes
This patch fixes following problems:
- does not allow the m parameter to reach 0 as
it locks the graphics core (power cycle needed)
- for the newer chips (with new clock registers)
does not allow of n / m ratio below 4 as it gives
unstable image on the Blade3D core
- extend shift parameter (k) range to 2 for the newer
chips to cope with the n /m >= 4 limit at low resolution
(bandwidth) modes
- prefer modes with higher n / m ratio (higher k values)
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/tridentfb.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/video/tridentfb.c b/drivers/video/tridentfb.c index 138140bdb495..854e2e5af582 100644 --- a/drivers/video/tridentfb.c +++ b/drivers/video/tridentfb.c @@ -672,15 +672,16 @@ static void set_vclk(struct tridentfb_par *par, unsigned long freq) unsigned long fi, d, di; unsigned char best_m = 0, best_n = 0, best_k = 0; unsigned char hi, lo; + unsigned char shift = !is_oldclock(par->chip_id) ? 2 : 1; d = 20000; - for (k = 1; k >= 0; k--) - for (m = 0; m < 32; m++) { - n = 2 * (m + 2) - 8; + for (k = shift; k >= 0; k--) + for (m = 1; m < 32; m++) { + n = ((m + 2) << shift) - 8; for (n = (n < 0 ? 0 : n); n < 122; n++) { fi = ((14318l * (n + 8)) / (m + 2)) >> k; di = abs(fi - freq); - if (di <= d) { + if (di < d || (di == d && k == best_k)) { d = di; best_n = n; best_m = m; |