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* [PATCH] Remove voodoo code from i2c
@ 2004-03-05 21:52 Kronos
  2004-03-05 23:55 ` Benjamin Herrenschmidt
  2004-03-06  0:12 ` Michel Dänzer
  0 siblings, 2 replies; 10+ messages in thread
From: Kronos @ 2004-03-05 21:52 UTC (permalink / raw)
  To: Benjamin Herrenschmidt; +Cc: linux-fbdev-devel

Hi,
radeon_probe_i2c_connector contains very strange code that just send
empty start-stop sequencies on the I2C bus. I copied the code from
XFree86, but speaking with I2C gurus the general feeling is that this
code can go away without any harm. I tested it on 3 different setup (all
x86...) and it works well. I don't have any "old" monitor around to
fiddle with though.

Oh, if you think that this code should stay I'll send you another patch
to make it more readable.

===== drivers/video/aty/radeon_i2c.c 1.3 vs edited =====
--- 1.3/drivers/video/aty/radeon_i2c.c	Wed Feb 18 07:02:05 2004
+++ edited/drivers/video/aty/radeon_i2c.c	Fri Mar  5 22:44:21 2004
@@ -180,59 +180,9 @@
 	OUTREG(reg, INREG(reg) & 
 			~(VGA_DDC_DATA_OUTPUT | VGA_DDC_CLK_OUTPUT));
 
-	OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN));
-	(void)INREG(reg);
-
 	for (i = 0; i < 3; i++) {
-		/* For some old monitors we need the
-		 * following process to initialize/stop DDC
-		 */
-		OUTREG(reg, INREG(reg) & ~(VGA_DDC_DATA_OUT_EN));
-		(void)INREG(reg);
-		wait_ms(13);
-
-		OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN));
-		(void)INREG(reg);
-		for (j = 0; j < 5; j++) {
-			wait_ms(10);
-			if (INREG(reg) & VGA_DDC_CLK_INPUT)
-				break;
-		}
-		if (j == 5)
-			continue;
-
-		OUTREG(reg, INREG(reg) | VGA_DDC_DATA_OUT_EN);
-		(void)INREG(reg);
-		wait_ms(15);
-		OUTREG(reg, INREG(reg) | VGA_DDC_CLK_OUT_EN);
-		(void)INREG(reg);
-		wait_ms(15);
-		OUTREG(reg, INREG(reg) & ~(VGA_DDC_DATA_OUT_EN));
-		(void)INREG(reg);
-		wait_ms(15);
-
 		/* Do the real work */
 		edid = radeon_do_probe_i2c_edid(&rinfo->i2c[conn-1]);
-
-		OUTREG(reg, INREG(reg) | 
-				(VGA_DDC_DATA_OUT_EN | VGA_DDC_CLK_OUT_EN));
-		(void)INREG(reg);
-		wait_ms(15);
-		
-		OUTREG(reg, INREG(reg) & ~(VGA_DDC_CLK_OUT_EN));
-		(void)INREG(reg);
-		for (j = 0; j < 10; j++) {
-			wait_ms(10);
-			if (INREG(reg) & VGA_DDC_CLK_INPUT)
-				break;
-		}
-
-		OUTREG(reg, INREG(reg) & ~(VGA_DDC_DATA_OUT_EN));
-		(void)INREG(reg);
-		wait_ms(15);
-		OUTREG(reg, INREG(reg) |
-				(VGA_DDC_DATA_OUT_EN | VGA_DDC_CLK_OUT_EN));
-		(void)INREG(reg);
 		if (edid)
 			break;
 	}

Luca
-- 
Home: http://kronoz.cjb.net
Runtime error 6D at f000:a12f : user incompetente


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^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2004-03-08 23:16 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2004-03-05 21:52 [PATCH] Remove voodoo code from i2c Kronos
2004-03-05 23:55 ` Benjamin Herrenschmidt
2004-03-06  0:47   ` Kronos
2004-03-06  2:10     ` Jon Smirl
2004-03-06  3:42       ` Benjamin Herrenschmidt
2004-03-06  4:02         ` Jon Smirl
2004-03-06 15:08       ` Kronos
2004-03-08 22:17   ` Richard Smith
2004-03-08 22:56     ` Benjamin Herrenschmidt
2004-03-06  0:12 ` Michel Dänzer

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