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-rw-r--r--src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c b/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c
index de721a1e83..05ad2d7b5c 100644
--- a/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c
+++ b/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c
@@ -46,6 +46,21 @@ static inline void smbus_delay(void)
outb(0x80, 0x80);
}
+static int smbus_wait_until_active(void)
+{
+ unsigned long loops;
+ loops = SMBUS_TIMEOUT;
+ do {
+ unsigned char val;
+ smbus_delay();
+ val = inb(SMBUS_IO_BASE + SMBHSTSTAT);
+ if ((val & 1)) {
+ break;
+ }
+ } while(--loops);
+ return loops?0:-4;
+}
+
static int smbus_wait_until_ready(void)
{
unsigned long loops;
@@ -112,7 +127,10 @@ static int smbus_read_byte(unsigned device, unsigned address)
/* start a byte read, with interrupts disabled */
outb((inb(SMBUS_IO_BASE + SMBHSTCTL) | 0x40), SMBUS_IO_BASE + SMBHSTCTL);
-
+ /* poll for it to start */
+ if (smbus_wait_until_active() < 0) {
+ return -4;
+ }
/* poll for transaction completion */
if (smbus_wait_until_done() < 0) {