Commit 8690ba44 authored by David Miller's avatar David Miller Committed by Linus Torvalds

[PATCH] video/aty/mach64_ct.c: fix bogus delay loop

CT based mach64 cards were reported to hang on sparc64 boxes when
compiled with gcc-4.1.x and later.

Looking at this piece of code, it's no surprise.  A critical
delay was implemented as an empty for() loop, and gcc 4.0.x
and previous did not optimize it away, so we did get a delay.

But gcc-4.1.x and later can optimize it away, and we get crashes.

Use a real udelay() to fix this.  Fix verified on SunBlade100.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8f485612
...@@ -598,7 +598,6 @@ static void aty_resume_pll_ct(const struct fb_info *info, ...@@ -598,7 +598,6 @@ static void aty_resume_pll_ct(const struct fb_info *info,
struct atyfb_par *par = info->par; struct atyfb_par *par = info->par;
if (par->mclk_per != par->xclk_per) { if (par->mclk_per != par->xclk_per) {
int i;
/* /*
* This disables the sclk, crashes the computer as reported: * This disables the sclk, crashes the computer as reported:
* aty_st_pll_ct(SPLL_CNTL2, 3, info); * aty_st_pll_ct(SPLL_CNTL2, 3, info);
...@@ -614,7 +613,7 @@ static void aty_resume_pll_ct(const struct fb_info *info, ...@@ -614,7 +613,7 @@ static void aty_resume_pll_ct(const struct fb_info *info,
* helps for Rage Mobilities that sometimes crash when * helps for Rage Mobilities that sometimes crash when
* we switch to sclk. (Daniel Mantione, 13-05-2003) * we switch to sclk. (Daniel Mantione, 13-05-2003)
*/ */
for (i=0;i<=0x1ffff;i++); udelay(500);
} }
aty_st_pll_ct(PLL_REF_DIV, pll->ct.pll_ref_div, par); aty_st_pll_ct(PLL_REF_DIV, pll->ct.pll_ref_div, par);
......
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