GNUBoot
/
coreboot-kgpe-d16
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

google/chromeec: Ensure data is ready before reading it 

Before reading the data provided by EC to the host, ensure that data
ready flag is set. Otherwise, it could result in reading stale/incorrect
data from the data buffer.

BUG=chrome-os-partner:56395
BRANCH=None
TEST=Verified that lidclose event is read correctly by host on reef.

Change-Id: I88e345d64256af8325b3dbf670467d09f09420f0
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/16258
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
This commit is contained in:
Furquan Shaikh 2016-08-18 21:39:14 -07:00
parent 3828e55a8c
commit 63e424cec2
1 changed files with 20 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
src/ec/google/chromeec/ec_lpc.c
View File

@ -96,7 +96,7 @@ static inline u8 write_byte(u8 val, u16 port)
return byte; return byte;
} }
static int google_chromeec_wait_ready(u16 port) static int google_chromeec_status_check(u16 port, u8 mask, u8 cond)
{ {
u8 ec_status = read_byte(port); u8 ec_status = read_byte(port);
u32 time_count = 0; u32 time_count = 0;
@ -108,8 +108,7 @@ static int google_chromeec_wait_ready(u16 port)
*/ */
#define MAX_EC_TIMEOUT_US 1000000 #define MAX_EC_TIMEOUT_US 1000000
while (ec_status & while ((ec_status & mask) != cond) {
(EC_LPC_CMDR_PENDING | EC_LPC_CMDR_BUSY)) {
udelay(1); udelay(1);
if (time_count++ == MAX_EC_TIMEOUT_US) if (time_count++ == MAX_EC_TIMEOUT_US)
return -1; return -1;
@ -118,6 +117,13 @@ static int google_chromeec_wait_ready(u16 port)
return 0; return 0;
} }
static int google_chromeec_wait_ready(u16 port)
{
return google_chromeec_status_check(port,
EC_LPC_CMDR_PENDING |
EC_LPC_CMDR_BUSY, 0);
}
#if CONFIG_EC_GOOGLE_CHROMEEC_ACPI_MEMMAP #if CONFIG_EC_GOOGLE_CHROMEEC_ACPI_MEMMAP
/* Read memmap data through ACPI port 66/62 */ /* Read memmap data through ACPI port 66/62 */
static int read_memmap(u8 *data, u8 offset) static int read_memmap(u8 *data, u8 offset)
@ -481,6 +487,12 @@ struct chip_operations ec_google_chromeec_ops = {
#endif /* __SMM__ */ #endif /* __SMM__ */
static int google_chromeec_data_ready(u16 port)
{
return google_chromeec_status_check(port, EC_LPC_CMDR_DATA,
EC_LPC_CMDR_DATA);
}
u8 google_chromeec_get_event(void) u8 google_chromeec_get_event(void)
{ {
if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) { if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
@ -496,6 +508,11 @@ u8 google_chromeec_get_event(void)
return 0; return 0;
} }
if (google_chromeec_data_ready(EC_LPC_ADDR_ACPI_CMD)) {
printk(BIOS_ERR, "Timeout waiting for data ready!\n");
return 0;
}
/* Event (or 0 if none) is returned directly in the data byte */ /* Event (or 0 if none) is returned directly in the data byte */
return read_byte(EC_LPC_ADDR_ACPI_DATA); return read_byte(EC_LPC_ADDR_ACPI_DATA);
} }