From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
For transfer counts > 255 bytes, the Blackfin TWI peripheral sets the
data transfer counter DCNT to 0xFF indicating unlimited transfers. It
then uses a flag iface->manual_stop to manually issue the STOP condition
once the required amount of bytes are received.
It seems that if the STOP condition is issued with a full receive fifo,
the TWI logic constantly drives the SDA/SCL lines low thus locking the
bus. So to make sure this doesn't happen, consume the fifo first.
Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-bfin-twi.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index 52b545a..5ed6c2f 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -131,6 +131,10 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface,
iface->transPtr++;
iface->readNum--;
} else if (iface->manual_stop) {
+ /* Avoid possible bus stall -
+ * Flush FIFO before issuing the STOP condition
+ */
+ read_RCV_DATA16(iface);
write_MASTER_CTL(iface,
read_MASTER_CTL(iface) | STOP);
} else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
--
1.7.5.rc3
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
