[PATCH] pm2fb: pixclock setting restriction

["Krzysztof Helt" <krzysztof.h1@wp.pl>]

[-- Attachment #1: Type: text/plain, Size: 744 bytes --]

From: Krzysztof Helt <krzysztof.h1@wp.pl>

This patch add restrictions to calculations of m, n and p factors
which sets the pixclock for the Permedia 2V. I found during tests
that synchronization is unstable if m (divisor) is bigger than
half of the n (numerator). The patch dissallows such settings
combination.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>

---



----------------------------------------------------
Już niedługo pierwsza komunia! Zrób naprawdę niezapomniany prezent:
Pięknie wydany i zilustrowany album do uzupełnienia przez dziecko
będzie na całe życie kroniką Pierwszej Komunii Świętej - Zobacz:
http://klik.wp.pl/?adr=http%3A%2F%2Fksiazka.eu%2F%3Fpg%3Dseria%26idseria%3D19%26ref%3Dwppl&sid=1113

[-- Attachment #2: pm2fb-p2v-pixclock-calc.diff --]
[-- Type: application/octet-stream, Size: 622 bytes --]

--- linux-2.6.21.orig/drivers/video/pm2fb.c	2007-04-21 21:34:34.672917412 +0200
+++ linux-2.6.21/drivers/video/pm2fb.c	2007-04-22 19:42:29.715214265 +0200
@@ -302,10 +303,10 @@ static void pm2v_mnp(u32 clk, unsigned c
 	s32 delta = 1000;
 
 	*mm = *nn = *pp = 0;
-	for (n = 1; n; n++) {
-		for ( m = 1; m; m++) {
+	for ( m = 1; m; m++) {
+		for (n = 2 * m + 1; n; n++) {
 			for ( p = 0; p < 2; p++) {
-				f = PM2_REFERENCE_CLOCK * n / (m * (1 << (p + 1)));
+				f = ( PM2_REFERENCE_CLOCK >> ( p + 1 )) * n / m;
 				if ( clk > f - delta && clk < f + delta ) {
 					delta = ( clk > f ) ? clk - f : f - clk;
 					*mm=m;

[-- Attachment #3: Type: text/plain, Size: 286 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/

[-- Attachment #4: Type: text/plain, Size: 182 bytes --]

_______________________________________________
Linux-fbdev-devel mailing list
Linux-fbdev-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-fbdev-devel