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* [PATCH] drm/i915: Reudce CHV DPLL min vco frequency to 4.8 GHz
@ 2015-02-26 19:01 ville.syrjala
  2015-03-01  3:52 ` shuang.he
  2015-03-04 14:41 ` Purushothaman, Vijay A
  0 siblings, 2 replies; 11+ messages in thread
From: ville.syrjala @ 2015-02-26 19:01 UTC (permalink / raw)
  To: intel-gfx

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

The current minimum vco frequency leaves us with a gap in our supported
frequencies at 233-243 MHz. Your typical 2560x1440@60 display wants a
pixel clock of 241.5 MHz, which is just withing that gap. Reduce the
allowed vco min frequency to 4.8GHz to reduce the gap to 233-240 MHz,
and thus allow such displays to work.

4.8 GHz is actually the documented (at least in some docs) limit of the
PLL, and we just picked 4.86 GHz originally because that was the lowest
value produced by the PLL spreadsheet, which obviously didn't consider
2560x1440 displays.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 102b12d..d437a21 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -390,7 +390,7 @@ static const intel_limit_t intel_limits_chv = {
 	 * them would make no difference.
 	 */
 	.dot = { .min = 25000 * 5, .max = 540000 * 5},
-	.vco = { .min = 4860000, .max = 6700000 },
+	.vco = { .min = 4800000, .max = 6700000 },
 	.n = { .min = 1, .max = 1 },
 	.m1 = { .min = 2, .max = 2 },
 	.m2 = { .min = 24 << 22, .max = 175 << 22 },
-- 
2.0.5

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^ permalink raw reply related	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2015-03-06 11:41 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-02-26 19:01 [PATCH] drm/i915: Reudce CHV DPLL min vco frequency to 4.8 GHz ville.syrjala
2015-03-01  3:52 ` shuang.he
2015-03-04 14:41 ` Purushothaman, Vijay A
2015-03-04 15:10   ` Ville Syrjälä
2015-03-04 15:15     ` Daniel Vetter
2015-03-05  7:43     ` checkpatch spell checking (was: Re: [PATCH] drm/i915: Reudce CHV DPLL min vco frequency to 4.8 GHz) Jani Nikula
2015-03-05 10:43       ` checkpatch spell checking (was: Re: [Intel-gfx] " Joe Perches
2015-03-05 16:57       ` [PATCH] checkpatch: Add spell checking of email subject line Joe Perches
2015-03-06  7:54         ` Jani Nikula
2015-03-06  8:40         ` [PATCH] checkpatch: spell check reudce Jani Nikula
2015-03-06 11:41           ` shuang.he

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