coreboot-kgpe-d16/payloads/libpayload/libc
Vadim Bendebury 1c5cdad09e libpayload: improve us timer accuracy
In cases where timer clock frequency is not an integer number of
megahertz, the calculations in timer_us() lack accuracy.

This patch modifies calculations to reduce the error. The maximum
interval this calculation would support decreases, but it still is in
excess of 1844674 seconds for a timer clocked by 10 MHz, which is more
than enough.

BUG=none
TEST=manual
  . verified timer accuracy using a depthcharge CLI command

Original-Change-Id: Iffb323db10e74b0ce3b4d59a56983bfee12e6805
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/207358
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit e1abf87d438de1a04714482d5b610671e8cc0663)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ia892726187ab040dd235f493c92856c15951cc06
Reviewed-on: http://review.coreboot.org/8128
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
2015-01-12 05:55:45 +01:00
..
Makefile.inc libpayload: Add a new "die" function to fatally signal programming errors. 2014-09-15 17:37:13 +02:00
args.c
console.c libpayload: Add ability to unregister output driver 2015-01-09 07:04:58 +01:00
ctype.c
die.c libpayload: Add a new "die" function to fatally signal programming errors. 2014-09-15 17:37:13 +02:00
exec.c libpayload: Change CONFIG_* to CONFIG_LP_* in the kconfig. 2014-08-05 18:44:08 +02:00
getopt_long.c Reduce warnings/errors in libpayload when using picky compiler options 2011-06-30 20:41:23 +02:00
hexdump.c libpayload: hexdump: Use `p` as conversion specifier for pointers 2014-12-19 21:15:05 +01:00
ipchecksum.c
lar.c Refactor the endianness conversion functions and header files. 2012-11-08 19:49:51 +01:00
lib.c libpayload: Provide dummy getenv() 2011-07-20 10:02:19 +02:00
malloc.c libpayload: Fix pointer related casts 2014-12-31 18:57:35 +01:00
memory.c libpayload: Reorder default memcpy, speed up memset and memcmp 2015-01-09 07:08:43 +01:00
printf.c libpayload: fix printf handling of unsigned long long 2014-12-30 20:54:23 +01:00
qsort.c libpayload: Fix whitespace errors 2013-06-27 14:46:43 +02:00
rand.c
readline.c
string.c libpayload: Add strerror 2013-06-28 10:39:57 +02:00
strings.c Reduce warnings/errors in libpayload when using picky compiler options 2011-06-30 20:41:23 +02:00
strlcpy.c libpayload: Implement strlcpy 2011-07-07 22:29:35 +02:00
sysinfo.c Reduce warnings/errors in libpayload when using picky compiler options 2011-06-30 20:41:23 +02:00
time.c libpayload: improve us timer accuracy 2015-01-12 05:55:45 +01:00