From: Ville Syrjälä Date: Thu, 1 Jun 2017 14:36:15 +0000 (+0300) Subject: drm/i915: Use a loop for the "three times for luck" DPLL procedure X-Git-Tag: v4.13-rc1~73^2~9^2~28 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=bb408dd2b2b040f7e483c21ed69353e80d890329;p=karo-tx-linux.git drm/i915: Use a loop for the "three times for luck" DPLL procedure The magic "enable the DPLL three times" sequence feels like it deserves a loop. Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/20170601143619.27840-4-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula Reviewed-by: Chris Wilson Reviewed-by: Maarten Lankhorst --- diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index efd7c5de5b5a..731800542159 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1550,6 +1550,7 @@ static void i9xx_enable_pll(struct intel_crtc *crtc) struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); i915_reg_t reg = DPLL(crtc->pipe); u32 dpll = crtc->config->dpll_hw_state.dpll; + int i; assert_pipe_disabled(dev_priv, crtc->pipe); @@ -1596,15 +1597,11 @@ static void i9xx_enable_pll(struct intel_crtc *crtc) } /* We do this three times for luck */ - I915_WRITE(reg, dpll); - POSTING_READ(reg); - udelay(150); /* wait for warmup */ - I915_WRITE(reg, dpll); - POSTING_READ(reg); - udelay(150); /* wait for warmup */ - I915_WRITE(reg, dpll); - POSTING_READ(reg); - udelay(150); /* wait for warmup */ + for (i = 0; i < 3; i++) { + I915_WRITE(reg, dpll); + POSTING_READ(reg); + udelay(150); /* wait for warmup */ + } } /**