From 577e0ee41563bcdc776da7d84a65e1bac3c6a3eb Mon Sep 17 00:00:00 2001 From: "Steven A. Falco" Date: Mon, 22 Apr 2013 09:34:39 +0000 Subject: i2c: xiic: must always write 16-bit words to TX_FIFO commit c39e8e4354ce4daf23336de5daa28a3b01f00aa6 upstream. The TX_FIFO register is 10 bits wide. The lower 8 bits are the data to be written, while the upper two bits are flags to indicate stop/start. The driver apparently attempted to optimize write access, by only writing a byte in those cases where the stop/start bits are zero. However, we have seen cases where the lower byte is duplicated onto the upper byte by the hardware, which causes inadvertent stop/starts. This patch changes the write access to the transmit FIFO to always be 16 bits wide. Signed off by: Steven A. Falco Signed-off-by: Wolfram Sang Signed-off-by: Ben Hutchings --- drivers/i2c/busses/i2c-xiic.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index 4bb68f35caf2..64e7065e8b86 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -311,10 +311,8 @@ static void xiic_fill_tx_fifo(struct xiic_i2c *i2c) /* last message in transfer -> STOP */ data |= XIIC_TX_DYN_STOP_MASK; dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); - - xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); - } else - xiic_setreg8(i2c, XIIC_DTR_REG_OFFSET, data); + } + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); } } -- cgit v1.2.3