From: Rayagonda Kokatanur rayagonda.kokatanur@broadcom.com
[ 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@kernel.org Signed-off-by: Rayagonda Kokatanur rayagonda.kokatanur@broadcom.com Reviewed-by: Ray Jui ray.jui@broadcom.com Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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++; } }