3.16.44-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Mc Guire <hofrat@xxxxxxxxx> commit 15a43cbf4736a3932e6259fa7d6e47558f6222b0 upstream. udelay_range(1, 2) is inefficient and as discussions with Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> 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 be4fc046bed3 ("drm/i915: add VLV DSI PLL Calculations") Link: http://lkml.org/lkml/2016/12/15/147 Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/1481853578-19834-1-git-send-email-hofrat@xxxxxxxxx Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_dsi_pll.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i915/intel_dsi_pll.c +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c @@ -265,8 +265,10 @@ void vlv_enable_dsi_pll(struct intel_enc vlv_configure_dsi_pll(encoder); - /* 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); tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL); tmp |= DSI_PLL_VCO_EN;