From: Akhil R akhilrajeev@nvidia.com
[ Upstream commit 9f855779a3874eee70e9f6be57b5f7774f14e510 ]
Update the msg->len value correctly for SMBUS block read. The discrepancy went unnoticed as msg->len is used in SMBUS transfers only when a PEC byte is added.
Fixes: d7583c8a5748 ("i2c: tegra: Add SMBus block read function") Signed-off-by: Akhil R akhilrajeev@nvidia.com Acked-by: Thierry Reding treding@nvidia.com Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-tegra.c | 40 +++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 13 deletions(-)
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 3869c258a5296..2bc40f957e509 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -242,9 +242,10 @@ struct tegra_i2c_hw_feature { * @is_dvc: identifies the DVC I2C controller, has a different register layout * @is_vi: identifies the VI I2C controller, has a different register layout * @msg_complete: transfer completion notifier + * @msg_buf_remaining: size of unsent data in the message buffer + * @msg_len: length of message in current transfer * @msg_err: error code for completed message * @msg_buf: pointer to current message data - * @msg_buf_remaining: size of unsent data in the message buffer * @msg_read: indicates that the transfer is a read access * @timings: i2c timings information like bus frequency * @multimaster_mode: indicates that I2C controller is in multi-master mode @@ -277,6 +278,7 @@ struct tegra_i2c_dev {
struct completion msg_complete; size_t msg_buf_remaining; + unsigned int msg_len; int msg_err; u8 *msg_buf;
@@ -1169,7 +1171,7 @@ static void tegra_i2c_push_packet_header(struct tegra_i2c_dev *i2c_dev, else i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
- packet_header = msg->len - 1; + packet_header = i2c_dev->msg_len - 1;
if (i2c_dev->dma_mode && !i2c_dev->msg_read) *dma_buf++ = packet_header; @@ -1242,20 +1244,32 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, return err;
i2c_dev->msg_buf = msg->buf; + i2c_dev->msg_len = msg->len;
- /* The condition true implies smbus block read and len is already read */ - if (msg->flags & I2C_M_RECV_LEN && end_state != MSG_END_CONTINUE) - i2c_dev->msg_buf = msg->buf + 1; - - i2c_dev->msg_buf_remaining = msg->len; i2c_dev->msg_err = I2C_ERR_NONE; i2c_dev->msg_read = !!(msg->flags & I2C_M_RD); reinit_completion(&i2c_dev->msg_complete);
+ /* + * For SMBUS block read command, read only 1 byte in the first transfer. + * Adjust that 1 byte for the next transfer in the msg buffer and msg + * length. + */ + if (msg->flags & I2C_M_RECV_LEN) { + if (end_state == MSG_END_CONTINUE) { + i2c_dev->msg_len = 1; + } else { + i2c_dev->msg_buf += 1; + i2c_dev->msg_len -= 1; + } + } + + i2c_dev->msg_buf_remaining = i2c_dev->msg_len; + if (i2c_dev->msg_read) - xfer_size = msg->len; + xfer_size = i2c_dev->msg_len; else - xfer_size = msg->len + I2C_PACKET_HEADER_SIZE; + xfer_size = i2c_dev->msg_len + I2C_PACKET_HEADER_SIZE;
xfer_size = ALIGN(xfer_size, BYTES_PER_FIFO_WORD);
@@ -1295,7 +1309,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, if (!i2c_dev->msg_read) { if (i2c_dev->dma_mode) { memcpy(i2c_dev->dma_buf + I2C_PACKET_HEADER_SIZE, - msg->buf, msg->len); + msg->buf, i2c_dev->msg_len);
dma_sync_single_for_device(i2c_dev->dma_dev, i2c_dev->dma_phys, @@ -1352,7 +1366,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, i2c_dev->dma_phys, xfer_size, DMA_FROM_DEVICE);
- memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf, msg->len); + memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf, i2c_dev->msg_len); } }
@@ -1408,8 +1422,8 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], MSG_END_CONTINUE); if (ret) break; - /* Set the read byte as msg len */ - msgs[i].len = msgs[i].buf[0]; + /* Set the msg length from first byte */ + msgs[i].len += msgs[i].buf[0]; dev_dbg(i2c_dev->dev, "reading %d bytes\n", msgs[i].len); } ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);