pm3fb: 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/pm3fb.c b/drivers/video/pm3fb.c
index 6a64b93..0706599 100644
--- a/drivers/video/pm3fb.c
+++ b/drivers/video/pm3fb.c
@@ -110,7 +110,8 @@
static inline void PM3_WAIT(struct pm3_par *par, u32 n)
{
- while (PM3_READ_REG(par, PM3InFIFOSpace) < n);
+ while (PM3_READ_REG(par, PM3InFIFOSpace) < n)
+ cpu_relax();
}
static inline void PM3_WRITE_DAC_REG(struct pm3_par *par, unsigned r, u8 v)
@@ -209,8 +210,8 @@
PM3_WRITE_REG(par, PM3Sync, 0);
mb();
do {
- while ((PM3_READ_REG(par, PM3OutFIFOWords)) == 0);
- rmb();
+ while ((PM3_READ_REG(par, PM3OutFIFOWords)) == 0)
+ cpu_relax();
} while ((PM3_READ_REG(par, PM3OutputFifo)) != PM3Sync_Tag);
return 0;