From: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
[ Upstream commit fd01eecdf9591453177d7b06faaabef8c300114a ]
Use SMBUS_MASTER_DATA_READ.MASTER_RD_STATUS bit to check for RX
FIFO empty condition because SMBUS_MASTER_FIFO_CONTROL.MASTER_RX_PKT_COUNT
is not updated for read >= 64 bytes. This fixes the issue when trying to
read from the I2C slave more than 63 bytes.
Fixes: c24b8d574b7c ("i2c: iproc: Extend I2C read up to 255 bytes")
Cc: stable@xxxxxxxxxx
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index a845b8decac8f..ad1681872e39d 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -403,16 +403,18 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
{
struct i2c_msg *msg = iproc_i2c->msg;
+ uint32_t val;
/* Read valid data from RX FIFO */
while (iproc_i2c->rx_bytes < msg->len) {
- if (!((iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET) >> M_FIFO_RX_CNT_SHIFT)
- & M_FIFO_RX_CNT_MASK))
+ val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET);
+
+ /* rx fifo empty */
+ if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK))
break;
msg->buf[iproc_i2c->rx_bytes] =
- (iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET) >>
- M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
+ (val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
iproc_i2c->rx_bytes++;
}
}
--
2.20.1
