pm2fb: replace busy waiting with cpu_relax
This patch replaces busy waiting with the cpu_relax() call. This makes
scrolling faster.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/pm2fb.c b/drivers/video/pm2fb.c
index 9db1f2e..5591dfb 100644
--- a/drivers/video/pm2fb.c
+++ b/drivers/video/pm2fb.c
@@ -193,8 +193,8 @@
#else
static inline void WAIT_FIFO(struct pm2fb_par *p, u32 a)
{
- while (pm2_RD(p, PM2R_IN_FIFO_SPACE) < a);
- mb();
+ while (pm2_RD(p, PM2R_IN_FIFO_SPACE) < a)
+ cpu_relax();
}
#endif
@@ -328,7 +328,7 @@
pm2_WR(p, PM2R_RESET_STATUS, 0);
mb();
while (pm2_RD(p, PM2R_RESET_STATUS) & PM2F_BEING_RESET)
- ;
+ cpu_relax();
mb();
#ifdef CONFIG_FB_PM2_FIFO_DISCONNECT
DPRINTK("FIFO disconnect enabled\n");
@@ -1041,8 +1041,7 @@
mb();
do {
while (pm2_RD(par, PM2R_OUT_FIFO_WORDS) == 0)
- udelay(10);
- rmb();
+ cpu_relax();
} while (pm2_RD(par, PM2R_OUT_FIFO) != PM2TAG(PM2R_SYNC));
return 0;