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[3/3] fbdev: sh_mobile_lcdc: Compute clock pattern using divider denominator

Message ID 1310766753-30314-4-git-send-email-laurent.pinchart@ideasonboard.com (mailing list archive)
State New, archived
Headers show

Commit Message

Laurent Pinchart July 15, 2011, 9:52 p.m. UTC 
The clock divider pattern is computed based on the dot clock register
value which stores the divider denumerator. However, when using a 1:1
divider ratio, the register is programmed with a value that must not be
interpreted as a denominator. This results in a shift left operation
with a value of 32, which produces undefined behaviour.

Compute the clock pattern using the divider denominator, not the dot
clock register value.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/video/sh_mobile_lcdcfb.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
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Patch

diff --git a/drivers/video/sh_mobile_lcdcfb.c b/drivers/video/sh_mobile_lcdcfb.c
index 32f884e..856f6a9 100644
--- a/drivers/video/sh_mobile_lcdcfb.c
+++ b/drivers/video/sh_mobile_lcdcfb.c
@@ -481,13 +481,15 @@  static int sh_mobile_lcdc_start(struct sh_mobile_lcdc_priv *priv)
 		if (!m)
 			continue;
 
+		/* FIXME: sh7724 can only use 42, 48, 54 and 60 for the divider
+		 * denominator.
+		 */
+		lcdc_write_chan(ch, LDDCKPAT1R, 0);
+		lcdc_write_chan(ch, LDDCKPAT2R, (1 << (m/2)) - 1);
+
 		if (m == 1)
 			m = LDDCKR_MOSEL;
 		tmp |= m << (lcdc_chan_is_sublcd(ch) ? 8 : 0);
-
-		/* FIXME: sh7724 can only use 42, 48, 54 and 60 for the divider denominator */
-		lcdc_write_chan(ch, LDDCKPAT1R, 0);
-		lcdc_write_chan(ch, LDDCKPAT2R, (1 << (m/2)) - 1);
 	}
 
 	lcdc_write(priv, _LDDCKR, tmp);