On Thu, Mar 2, 2017 at 8:55 PM, Jaedon Shin <jaedon.shin@xxxxxxxxx> wrote:
> The BSC data buffers to send and receive data are each of size 32 bytes
> or 8 bytes 'xfersz' depending on SoC. The problem observed for all the
> combined message transfer was if length of data transfer was a multiple
> of 'xfersz' a repeated START was being transmitted by BSC driver. Fixed
> this by appropriately setting START/STOP conditions for such transfers.
>
> Fixes: dd1aa2524bc5 ("i2c: brcmstb: Add Broadcom settop SoC i2c controller driver")
> Signed-off-by: Jaedon Shin <jaedon.shin@xxxxxxxxx>
Acked-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-brcmstb.c | 27 +++++++++++++++++++++------
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-brcmstb.c b/drivers/i2c/busses/i2c-brcmstb.c
> index 0652281662a8..78792b4d6437 100644
> --- a/drivers/i2c/busses/i2c-brcmstb.c
> +++ b/drivers/i2c/busses/i2c-brcmstb.c
> @@ -465,6 +465,7 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> u8 *tmp_buf;
> int len = 0;
> int xfersz = brcmstb_i2c_get_xfersz(dev);
> + u32 cond, cond_per_msg;
>
> if (dev->is_suspended)
> return -EBUSY;
> @@ -481,10 +482,11 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
>
> if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
> - brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
> + cond = ~COND_START_STOP;
> else
> - brcmstb_set_i2c_start_stop(dev,
> - COND_RESTART | COND_NOSTOP);
> + cond = COND_RESTART | COND_NOSTOP;
> +
> + brcmstb_set_i2c_start_stop(dev, cond);
>
> /* Send slave address */
> if (!(pmsg->flags & I2C_M_NOSTART)) {
> @@ -497,13 +499,24 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> }
> }
>
> + cond_per_msg = cond;
> +
> /* Perform data transfer */
> while (len) {
> bytes_to_xfer = min(len, xfersz);
>
> - if (len <= xfersz && i == (num - 1))
> - brcmstb_set_i2c_start_stop(dev,
> - ~(COND_START_STOP));
> + if (len <= xfersz) {
> + if (i == (num - 1))
> + cond_per_msg = cond_per_msg &
> + ~(COND_RESTART | COND_NOSTOP);
> + else
> + cond_per_msg = cond;
> + } else {
> + cond_per_msg = (cond_per_msg & ~COND_RESTART) |
> + COND_NOSTOP;
> + }
> +
> + brcmstb_set_i2c_start_stop(dev, cond_per_msg);
>
> rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
> bytes_to_xfer, pmsg);
> @@ -512,6 +525,8 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
>
> len -= bytes_to_xfer;
> tmp_buf += bytes_to_xfer;
> +
> + cond_per_msg = COND_NOSTART | COND_NOSTOP;
> }
> }
>
> --
> 2.12.0
>
--
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
