So apparently the pll limits in the docs are the real values, but the formula actually seems to consistenly use register values. See commit 4f7dfb6788dd022446847fbbfbe45e13bedb5be2 Author: Patrik Jakobsson <patrik.r.jakobsson at gmail.com> Date: Wed Feb 13 22:20:22 2013 +0100 drm/i915: Set i9xx sdvo clock limits according to specifications On gen2 the situation is a bit more messy: We reuse the code for m1/m2/n computation and register frobbing from gen3, so those limits need to be in register values (and so need to substract 2 from the doc limits). But gen2 also stores p1/p2 with 2/1 substracted in the register! For those though i8xx_update_pll does the adjustments, but the clock computation code assumes it works like on gen3. So for divisor limits we must _not_ adjust them to the register values. v2: Extract the common i8xx m/n limits into a single define. This was motivated by the mess for the g4x limits where they've all been off in different directions, apparently to fix specific bugs ... Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/intel_display.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 959c2ae..ea8eb0c 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -84,13 +84,16 @@ intel_fdi_link_freq(struct drm_device *dev) return 27; } +#define I8XX_DPLL_M_N_LIMITS \ + .n = { .min = 1, .max = 14 }, \ + .m = { .min = 96, .max = 140 }, \ + .m1 = { .min = 16, .max = 24 }, \ + .m2 = { .min = 4, .max = 14 }, + static const intel_limit_t intel_limits_i8xx_dvo = { .dot = { .min = 25000, .max = 350000 }, .vco = { .min = 930000, .max = 1400000 }, - .n = { .min = 3, .max = 16 }, - .m = { .min = 96, .max = 140 }, - .m1 = { .min = 18, .max = 26 }, - .m2 = { .min = 6, .max = 16 }, + I8XX_DPLL_M_N_LIMITS .p = { .min = 4, .max = 128 }, .p1 = { .min = 2, .max = 33 }, .p2 = { .dot_limit = 165000, @@ -100,10 +103,7 @@ static const intel_limit_t intel_limits_i8xx_dvo = { static const intel_limit_t intel_limits_i8xx_lvds = { .dot = { .min = 25000, .max = 350000 }, .vco = { .min = 930000, .max = 1400000 }, - .n = { .min = 3, .max = 16 }, - .m = { .min = 96, .max = 140 }, - .m1 = { .min = 18, .max = 26 }, - .m2 = { .min = 6, .max = 16 }, + I8XX_DPLL_M_N_LIMITS .p = { .min = 4, .max = 128 }, .p1 = { .min = 1, .max = 6 }, .p2 = { .dot_limit = 165000, -- 1.7.11.7