diff options
| author | Rob Barnes <robbarnes@google.com> | 2021-03-24 12:25:26 -0600 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2021-04-29 05:24:00 +0000 |
| commit | 51c4d9fbfd9611978627ce6111b1083379a4b829 (patch) | |
| tree | 954887466c0844a45f6d097e0fa8a844602e40d8 /src/ec | |
| parent | f3e82459a8ea0fa0ec92e458a92cd20effcfef3a (diff) | |
chromeec: Fix google_chromeec_status_check timeout
Rewrite google_chromeec_status_check to use stopwatch instead of a
delay in a while loop. In practice the while loop ends up taking
much longer than one second to timeout. Using stopwatch library will
accurately timeout after one second.
BUG=b:183524609
TEST=Build and run on guybrush
BRANCH=None
Change-Id: I363ff7453bcf81581884f92797629a6f96d42580
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51775
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Diffstat (limited to 'src/ec')
| -rw-r--r-- | src/ec/google/chromeec/ec_lpc.c | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/src/ec/google/chromeec/ec_lpc.c b/src/ec/google/chromeec/ec_lpc.c index b9c972834b..3b2a7465a3 100644 --- a/src/ec/google/chromeec/ec_lpc.c +++ b/src/ec/google/chromeec/ec_lpc.c @@ -7,6 +7,7 @@ #include <device/pnp.h> #include <ec/google/common/mec.h> #include <stdint.h> +#include <timer.h> #include "chip.h" #include "ec.h" @@ -92,23 +93,19 @@ static inline u8 write_byte(u8 val, u16 port) static int google_chromeec_status_check(u16 port, u8 mask, u8 cond) { - u8 ec_status = read_byte(port); - u32 time_count = 0; - - /* - * One second is more than plenty for any EC operation to complete - * (and the bus accessing/code execution) overhead will make the - * timeout even longer. - */ -#define MAX_EC_TIMEOUT_US 1000000 - - while ((ec_status & mask) != cond) { - udelay(1); - if (time_count++ == MAX_EC_TIMEOUT_US) - return -1; - ec_status = read_byte(port); - } - return 0; + struct stopwatch timeout_sw; + /* One second is more than plenty for any EC operation to complete */ + const uint64_t ec_status_timeout_us = 1 * USECS_PER_SEC; + /* Wait 1 usec between read attempts */ + const uint64_t ec_status_read_period_us = 1; + + stopwatch_init_usecs_expire(&timeout_sw, ec_status_timeout_us); + do { + if ((read_byte(port) & mask) == cond) + return 0; + udelay(ec_status_read_period_us); + } while (!stopwatch_expired(&timeout_sw)); + return -1; } static int google_chromeec_wait_ready(u16 port) |