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authorChris Wilson <chris@chris-wilson.co.uk>2013-09-25 14:24:01 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-20 07:49:10 -0800
commitfd7a5ac9b59e74544181598fba54fd843b878db4 (patch)
treeca4bfe9261efc1fb55dbd078141a3fe3e6ed9278
parent7870bfa3a3516aa89db7c7260fa0e524850b2a56 (diff)
drm/i915/vlv: fix up broken precision in vlv_crtc_clock_get
commit 662c6ecbcdca1fe8a5402f6c83d98d242917a043 upstream. With some divider values we end up with the wrong result. So remove the intermediates (like Ville suggested in the first place) to get the right answer. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i915/intel_display.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8abe7970f2b7..f535670b42d1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5040,7 +5040,7 @@ static void vlv_crtc_clock_get(struct intel_crtc *crtc,
int pipe = pipe_config->cpu_transcoder;
intel_clock_t clock;
u32 mdiv;
- int refclk = 100000, fastclk, update_rate;
+ int refclk = 100000;
mutex_lock(&dev_priv->dpio_lock);
mdiv = vlv_dpio_read(dev_priv, DPIO_DIV(pipe));
@@ -5052,10 +5052,8 @@ static void vlv_crtc_clock_get(struct intel_crtc *crtc,
clock.p1 = (mdiv >> DPIO_P1_SHIFT) & 7;
clock.p2 = (mdiv >> DPIO_P2_SHIFT) & 0x1f;
- update_rate = refclk / clock.n;
- clock.vco = update_rate * clock.m1 * clock.m2;
- fastclk = clock.vco / clock.p1 / clock.p2;
- clock.dot = (2 * fastclk);
+ clock.vco = refclk * clock.m1 * clock.m2 / clock.n;
+ clock.dot = 2 * clock.vco / (clock.p1 * clock.p2);
pipe_config->adjusted_mode.clock = clock.dot / 10;
}