Commit 021357ac authored by Chris Wilson's avatar Chris Wilson

drm/i915: Use the real FDI frequency for determining b/w

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
parent 8c4223be
......@@ -2398,6 +2398,7 @@
#define RR_HW_HIGH_POWER_FRAMES_MASK 0xff00
#define FDI_PLL_BIOS_0 0x46000
#define FDI_PLL_FB_CLOCK_MASK 0xff
#define FDI_PLL_BIOS_1 0x46004
#define FDI_PLL_BIOS_2 0x46008
#define DISPLAY_PORT_PLL_BIOS_0 0x4600c
......
......@@ -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 */
......
......@@ -49,6 +49,9 @@
#define wait_for(COND, MS) _wait_for(COND, MS, 1)
#define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
#define KHz(x) (1000*x)
#define MHz(x) KHz(1000*x)
/*
* Display related stuff
*/
......
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