[Linux-fbdev-devel] [PATCH] atyfb: Replace busy loop with mdelay()

[Ville <sy...@sc...>]

Replace a busy loop with mdelay() in atyfb clock setup code. This fixes
boot hangs several people have experienced.

Signed-off-by: Ville Syrjala <sy...@sc...>
---

This patch was already forwareded by James to some of you, but here it 
is with the proper changelog, signed-off-by line, and a language fix in 
the comment part. Also Cc:d st...@ke... as this seems like -stable 
material to me.

 drivers/video/aty/mach64_ct.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Index: linux-2.6.20.1/drivers/video/aty/mach64_ct.c
===================================================================
--- linux-2.6.20.1.orig/drivers/video/aty/mach64_ct.c
+++ linux-2.6.20.1/drivers/video/aty/mach64_ct.c
@@ -598,7 +598,6 @@ static void aty_resume_pll_ct(const stru
 	struct atyfb_par *par = info->par;
 
 	if (par->mclk_per != par->xclk_per) {
-		int i;
 		/*
 		* This disables the sclk, crashes the computer as reported:
 		* aty_st_pll_ct(SPLL_CNTL2, 3, info);
@@ -609,12 +608,10 @@ static void aty_resume_pll_ct(const stru
 		aty_st_pll_ct(SCLK_FB_DIV, pll->ct.sclk_fb_div, par);
 		aty_st_pll_ct(SPLL_CNTL2, pll->ct.spll_cntl2, par);
 		/*
-		 * The sclk has been started. However, I believe the first clock
-		 * ticks it generates are not very stable. Hope this primitive loop
-		 * helps for Rage Mobilities that sometimes crash when
-		 * we switch to sclk. (Daniel Mantione, 13-05-2003)
+		 * SCLK has been started. Wait for the PLL to lock. 5 ms
+		 * should be enough according to mach64 programmer's guide.
 		 */
-		for (i=0;i<=0x1ffff;i++);
+		mdelay(5);
 	}
 
 	aty_st_pll_ct(PLL_REF_DIV, pll->ct.pll_ref_div, par);

-- 
Ville Syrjälä
sy...@sc...
http://www.sci.fi/~syrjala/