From: Krzysztof Helt This patch replaces busy waiting with the cpu_relax() call. This makes scrolling faster. Signed-off-by: Krzysztof Helt Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton --- drivers/video/pm2fb.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff -puN drivers/video/pm2fb.c~pm2fb-replace-busy-waiting-with-cpu_relax drivers/video/pm2fb.c --- a/drivers/video/pm2fb.c~pm2fb-replace-busy-waiting-with-cpu_relax +++ a/drivers/video/pm2fb.c @@ -193,8 +193,8 @@ static inline void pm2v_RDAC_WR(struct p #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 @@ static void reset_card(struct pm2fb_par 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 @@ static int pm2fb_sync(struct fb_info *in 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; _