This is a simple optimization for fifo waiting that improves scrolling
performance by 5%. If the queue has more free entries that what we
consume, we can skip the costly register read next time.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/video/fbdev/aty/atyfb.h | 12 ++++++++----
drivers/video/fbdev/aty/mach64_accel.c | 4 +++-
2 files changed, 11 insertions(+), 5 deletions(-)
Index: linux-stable/drivers/video/fbdev/aty/atyfb.h
===================================================================
--- linux-stable.orig/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:49:16.000000000 +0200
+++ linux-stable/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:52:51.000000000 +0200
@@ -147,6 +147,7 @@ struct atyfb_par {
u16 pci_id;
u32 accel_flags;
int blitter_may_be_busy;
+ unsigned fifo_space;
int asleep;
int lock_blank;
unsigned long res_start;
@@ -346,10 +347,13 @@ extern int aty_init_cursor(struct fb_inf
* Hardware acceleration
*/
-static inline void wait_for_fifo(u16 entries, const struct atyfb_par *par)
+static inline void wait_for_fifo(u16 entries, struct atyfb_par *par)
{
- while ((aty_ld_le32(FIFO_STAT, par) & 0xffff) >
- ((u32) (0x8000 >> entries)));
+ unsigned fifo_space = par->fifo_space;
+ while (entries > fifo_space) {
+ fifo_space = 16 - fls(aty_ld_le32(FIFO_STAT, par) & 0xffff);
+ }
+ par->fifo_space = fifo_space - entries;
}
static inline void wait_for_idle(struct atyfb_par *par)
@@ -359,7 +363,7 @@ static inline void wait_for_idle(struct
par->blitter_may_be_busy = 0;
}
-extern void aty_reset_engine(const struct atyfb_par *par);
+extern void aty_reset_engine(struct atyfb_par *par);
extern void aty_init_engine(struct atyfb_par *par, struct fb_info *info);
void atyfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);
Index: linux-stable/drivers/video/fbdev/aty/mach64_accel.c
===================================================================
--- linux-stable.orig/drivers/video/fbdev/aty/mach64_accel.c 2018-08-25 21:49:16.000000000 +0200
+++ linux-stable/drivers/video/fbdev/aty/mach64_accel.c 2018-08-25 21:49:16.000000000 +0200
@@ -37,7 +37,7 @@ static u32 rotation24bpp(u32 dx, u32 dir
return ((rotation << 8) | DST_24_ROTATION_ENABLE);
}
-void aty_reset_engine(const struct atyfb_par *par)
+void aty_reset_engine(struct atyfb_par *par)
{
/* reset engine */
aty_st_le32(GEN_TEST_CNTL,
@@ -50,6 +50,8 @@ void aty_reset_engine(const struct atyfb
/* HOST errors */
aty_st_le32(BUS_CNTL,
aty_ld_le32(BUS_CNTL, par) | BUS_HOST_ERR_ACK | BUS_FIFO_ERR_ACK, par);
+
+ par->fifo_space = 0;
}
static void reset_GTC_3D_engine(const struct atyfb_par *par)
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