From 1e69cd74af22cce3b882b155bef295ff68a40566 Mon Sep 17 00:00:00 2001 From: Vidya Srinivas Date: Thu, 5 Mar 2015 21:19:50 +0200 Subject: [PATCH] drm/i915: Program PFI credits for VLV MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit PFI credit programming is required when CD clock (related to data flow from display pipeline to end display) is greater than CZ clock (related to data flow from memory to display plane). This programming should be done when all planes are OFF to avoid intermittent hangs while accessing memory even from different Gfx units (not just display). If cdclk/czclk >=1, PFI credits could be set as any number. To get better performance, larger PFI credit can be assigned to PND. Otherwise if cdclk/czclk<1, the default PFI credit of 8 should be set. v2: - Change log to lower log level instead of DRM_ERROR - Change function name to valleyview_program_pfi_credits - Move program PFI credits to modeset_init instead of intel_set_mode - Change magic numbers to logical constants [vsyrjala v3: - only program in response to cdclk update - program the credits also when cdclk Signed-off-by: Gajanan Bhat Signed-off-by: Vandana Kannan Signed-off-by: Ville Syrjälä Reviewed-by: Vijay Purushothaman Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_reg.h | 8 ++++++ drivers/gpu/drm/i915/intel_display.c | 38 ++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index ff60166875f3..8e29e2a6fe5c 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -2105,6 +2105,14 @@ enum skl_disp_power_wells { #define CDCLK_FREQ_SHIFT 4 #define CDCLK_FREQ_MASK (0x1f << CDCLK_FREQ_SHIFT) #define CZCLK_FREQ_MASK 0xf + +#define GCI_CONTROL (VLV_DISPLAY_BASE + 0x650C) +#define PFI_CREDIT_63 (9 << 28) /* chv only */ +#define PFI_CREDIT_31 (8 << 28) /* chv only */ +#define PFI_CREDIT(x) (((x) - 8) << 28) /* 8-15 */ +#define PFI_CREDIT_RESEND (1 << 27) +#define VGA_FAST_MODE_DISABLE (1 << 14) + #define GMBUSFREQ_VLV (VLV_DISPLAY_BASE + 0x6510) /* diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index cbf426ec92e3..70c95d363aa9 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -5100,6 +5100,42 @@ static void valleyview_modeset_global_pipes(struct drm_device *dev, *prepare_pipes |= (1 << intel_crtc->pipe); } +static void vlv_program_pfi_credits(struct drm_i915_private *dev_priv) +{ + unsigned int credits, default_credits; + + if (IS_CHERRYVIEW(dev_priv)) + default_credits = PFI_CREDIT(12); + else + default_credits = PFI_CREDIT(8); + + if (DIV_ROUND_CLOSEST(dev_priv->vlv_cdclk_freq, 1000) >= dev_priv->rps.cz_freq) { + /* CHV suggested value is 31 or 63 */ + if (IS_CHERRYVIEW(dev_priv)) + credits = PFI_CREDIT_31; + else + credits = PFI_CREDIT(15); + } else { + credits = default_credits; + } + + /* + * WA - write default credits before re-programming + * FIXME: should we also set the resend bit here? + */ + I915_WRITE(GCI_CONTROL, VGA_FAST_MODE_DISABLE | + default_credits); + + I915_WRITE(GCI_CONTROL, VGA_FAST_MODE_DISABLE | + credits | PFI_CREDIT_RESEND); + + /* + * FIXME is this guaranteed to clear + * immediately or should we poll for it? + */ + WARN_ON(I915_READ(GCI_CONTROL) & PFI_CREDIT_RESEND); +} + static void valleyview_modeset_global_resources(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -5123,6 +5159,8 @@ static void valleyview_modeset_global_resources(struct drm_device *dev) else valleyview_set_cdclk(dev, req_cdclk); + vlv_program_pfi_credits(dev_priv); + intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE_A); } } -- 2.20.1