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[PATCH 2/4] drm/sun4i: dotclock: Fix clock rate read back calcation

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When reading back the divider set in the register, we mask off the
bits that aren't part of the divider. Unfortunately the mask used
here was not converted from the field width.

Fix this by converting the field width to a proper bit mask.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 drivers/gpu/drm/sun4i/sun4i_dotclock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 4332da48b1b3..1b6c2253192e 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -62,7 +62,7 @@ static unsigned long sun4i_dclk_recalc_rate(struct clk_hw *hw,
 	regmap_read(dclk->regmap, SUN4I_TCON0_DCLK_REG, &val);
 
 	val >>= SUN4I_TCON0_DCLK_DIV_SHIFT;
-	val &= SUN4I_TCON0_DCLK_DIV_WIDTH;
+	val &= (1 << SUN4I_TCON0_DCLK_DIV_WIDTH) - 1;
 
 	if (!val)
 		val = 1;
-- 
2.9.3

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Thread

[PATCH 0/4] drm/sun4i: rgb and dotclock misc fixes and improvements Chen-Yu Tsai <wens@csie.org> - 2016-09-15 17:20 +0200
  [PATCH 1/4] drm/sun4i: rgb: Declare RGB encoder and connector as MIPI DPI Chen-Yu Tsai <wens@csie.org> - 2016-09-15 17:20 +0200
    Re: [PATCH 1/4] drm/sun4i: rgb: Declare RGB encoder and connector as  MIPI DPI Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-09-18 21:20 +0200
      Re: [PATCH 1/4] drm/sun4i: rgb: Declare RGB encoder and connector as  MIPI DPI Chen-Yu Tsai <wens@csie.org> - 2016-09-19 17:30 +0200
  [PATCH 2/4] drm/sun4i: dotclock: Fix clock rate read back calcation Chen-Yu Tsai <wens@csie.org> - 2016-09-15 17:20 +0200
    Re: [PATCH 2/4] drm/sun4i: dotclock: Fix clock rate read back  calcation Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-09-18 21:20 +0200
  [PATCH 4/4] drm/sun4i: dotclock: Round to closest clock rate Chen-Yu Tsai <wens@csie.org> - 2016-09-15 17:20 +0200
    Re: [PATCH 4/4] drm/sun4i: dotclock: Round to closest clock rate Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-09-18 21:20 +0200
      Re: [PATCH 4/4] drm/sun4i: dotclock: Round to closest clock rate Chen-Yu Tsai <wens@csie.org> - 2016-09-19 17:40 +0200
        Re: [PATCH 4/4] drm/sun4i: dotclock: Round to closest clock rate Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-09-20 17:50 +0200
    Re: [PATCH 4/4] drm/sun4i: dotclock: Round to closest clock rate Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-09-20 17:50 +0200
  [PATCH 3/4] drm/sun4i: dotclock: Allow divider = 127 Chen-Yu Tsai <wens@csie.org> - 2016-09-15 17:20 +0200
    Re: [PATCH 3/4] drm/sun4i: dotclock: Allow divider = 127 Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-09-18 21:20 +0200

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