From 021357acc8ea85273a9882b3fe89935629f51b12 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 7 Sep 2010 20:54:59 +0100 Subject: [PATCH] drm/i915: Use the real FDI frequency for determining b/w Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_display.c | 17 ++++++++++++++++- drivers/gpu/drm/i915/intel_drv.h | 3 +++ 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index d0b4b23..fbf58e0 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -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 diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index df410e4..5279b0c 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 */ diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 1ada684..6c6b897 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -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 */ -- 2.7.4