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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2010-09-07 20:54:59 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2010-09-10 23:13:51 +0100 |
| commit | 021357acc8ea85273a9882b3fe89935629f51b12 (patch) | |
| tree | 0b3203f90289d2f7e31b299d6804a8aa61fe407d /drivers/gpu/drm/i915/intel_display.c | |
| parent | 8c4223bee91b771782f2ec07f2c85d81cdff3ed5 (diff) | |
| download | lwn-021357acc8ea85273a9882b3fe89935629f51b12.tar.gz lwn-021357acc8ea85273a9882b3fe89935629f51b12.zip | |
drm/i915: Use the real FDI frequency for determining b/w
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_display.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index df410e4827e4..5279b0c88e9c 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -342,6 +342,13 @@ static bool intel_find_pll_ironlake_dp(const intel_limit_t *, struct drm_crtc *crtc, int target, int refclk, intel_clock_t *best_clock); +static inline u32 /* units of 100MHz */ +intel_fdi_link_freq(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + return (I915_READ(FDI_PLL_BIOS_0) & FDI_PLL_FB_CLOCK_MASK) + 2; +} + static const intel_limit_t intel_limits_i8xx_dvo = { .dot = { .min = I8XX_DOT_MIN, .max = I8XX_DOT_MAX }, .vco = { .min = I8XX_VCO_MIN, .max = I8XX_VCO_MAX }, @@ -3767,7 +3774,15 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc, target_clock = mode->clock; else target_clock = adjusted_mode->clock; - link_bw = 270000; + + /* FDI is a binary signal running at ~2.7GHz, encoding + * each output octet as 10 bits. The actual frequency + * is stored as a divider into a 100MHz clock, and the + * mode pixel clock is stored in units of 1KHz. + * Hence the bw of each lane in terms of the mode signal + * is: + */ + link_bw = intel_fdi_link_freq(dev) * MHz(100)/KHz(1)/10; } /* determine panel color depth */ |