[PATCH 04/36] drm/omap: remove divider constraint from hsdiv

Tomi Valkeinen tomi.valkeinen at ti.com
Wed Nov 30 11:17:06 UTC 2016


The driver only uses even dividers for hsdiv when pclk >= 100MHz, as odd
dividers can create uneven duty cycle. However, while this holds true
for some dividers like DISPC's LCK and PCK dividers, it is not actually
true for hsdiv.

hsdiv always produces even duty cycle, so the constraint can be removed.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
---
 drivers/gpu/drm/omapdrm/dss/dpi.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/dpi.c b/drivers/gpu/drm/omapdrm/dss/dpi.c
index e75162d26ac0..e0b0c5c24c55 100644
--- a/drivers/gpu/drm/omapdrm/dss/dpi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dpi.c
@@ -170,14 +170,6 @@ static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
 {
 	struct dpi_clk_calc_ctx *ctx = data;
 
-	/*
-	 * Odd dividers give us uneven duty cycle, causing problem when level
-	 * shifted. So skip all odd dividers when the pixel clock is on the
-	 * higher side.
-	 */
-	if (m_dispc > 1 && m_dispc % 2 != 0 && ctx->pck_min >= 100000000)
-		return false;
-
 	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
 	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;
 
-- 
2.7.4



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