Commit 15a43cbf authored Dec 16, 2016 by Nicholas Mc Guire Committed by Jani Nikula Dec 16, 2016

drm/i915: relax uncritical udelay_range()

udelay_range(1, 2) is inefficient and as discussions with Jani Nikula
<jani.nikula@linux.intel.com> unnecessary here. This replaces this
tight setting with a relaxed delay of min=20 and max=50 which helps
the hrtimer subsystem optimize timer handling.

Fixes: commit be4fc046 ("drm/i915: add VLV DSI PLL Calculations")
Link: http://lkml.org/lkml/2016/12/15/147


Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481853578-19834-1-git-send-email-hofrat@osadl.org

parent 0a7b35ce

drivers/gpu/drm/i915/intel_dsi_pll.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -156,8 +156,10 @@ static void vlv_enable_dsi_pll(struct intel_encoder *encoder,
		vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL,
		config->dsi_pll.ctrl & ~DSI_PLL_VCO_EN);

		/* wait at least 0.5 us after ungating before enabling VCO */
		usleep_range(1, 10);
		/* wait at least 0.5 us after ungating before enabling VCO,
		* allow hrtimer subsystem optimization by relaxing timing
		*/
		usleep_range(10, 50);

		vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, config->dsi_pll.ctrl);