From: Shiraz Hashim shiraz.hashim@st.com
Enable data cache with 1:1 mapping of DDR to enable fast file transfer over tty which was doing lot of copy.
This feature is enabled only for flashing operation i.e. when CONFIG_SPEAR_USBTTY is enabled.
This has been tested on SPEAr320, SPEAr600 and SPEAr900 evaluation boards.
Following figures show an estimate on the performance improvements. The test setup was a Linux host (not Windows) and involved measurement of only binary transfer time, through kermit. The flash erase and flash copy time would be unaffected by these patches.
Another thing is this that the timings remained more or less same across ARM9 and Cortex based devices, hence reporting only one of the cases.
Before Enhancements ===================
$ time ukermit.small -p /dev/ttyACM0 -f spear320_uImage.img Downloading file: 100.00% completed(2014080/2014080 bytes) real 0m41.228s user 0m0.002s sys 0m0.064s
After Enhancements ==================
$ time ukermit.large -p /dev/ttyACM0 -f spear320_uImage.img Downloading file: 100.00% completed(2014080/2014080 bytes) real 0m5.441s user 0m0.001s sys 0m0.001s
Signed-off-by: Shiraz Hashim shiraz.hashim@st.com Signed-off-by: Amit Virdi amit.virdi@st.com --- board/spear/common/spr_misc.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/board/spear/common/spr_misc.c b/board/spear/common/spr_misc.c index 043c72a..99a6595 100644 --- a/board/spear/common/spr_misc.c +++ b/board/spear/common/spr_misc.c @@ -76,6 +76,10 @@ int misc_init_r(void) setenv("stdin", "usbtty"); setenv("stdout", "usbtty"); setenv("stderr", "usbtty"); + +#ifndef CONFIG_SYS_NO_DCACHE + dcache_enable(); +#endif #endif return 0; }