From 597fe310f16d8246eec856326aa497bfa1b5bfa3 Mon Sep 17 00:00:00 2001 From: Shinya Kuribayashi Date: Fri, 6 Nov 2009 21:51:36 +0900 Subject: i2c-designware: Skip RX_FULL and TX_EMPTY bits on tx abort errors Suppose TX_ABRT occurs in the middle of processing i2c_msg msgs[], and a STOP condition has already been generated on the bus. In this case, subsequent i2c_dw_xfer_msg() might initiate a new and unnecessary I2C transaction, which we'd have to avoid. Furthermore, anytime TX_ABRT is set, the contents of tx/rx buffers are flushed, so we don't have to process RX_FULL and TX_EMPTY. Disable interrupts, and skip them. Signed-off-by: Shinya Kuribayashi Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-designware.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/i2c/busses/i2c-designware.c') diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c index cb83671ff5fc..e6b1e6ece5d7 100644 --- a/drivers/i2c/busses/i2c-designware.c +++ b/drivers/i2c/busses/i2c-designware.c @@ -621,6 +621,13 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) if (stat & DW_IC_INTR_TX_ABRT) { dev->cmd_err |= DW_IC_ERR_TX_ABRT; dev->status = STATUS_IDLE; + + /* + * Anytime TX_ABRT is set, the contents of the tx/rx + * buffers are flushed. Make sure to skip them. + */ + writel(0, dev->base + DW_IC_INTR_MASK); + goto tx_aborted; } if (stat & DW_IC_INTR_RX_FULL) @@ -635,6 +642,7 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) * the current transmit status. */ +tx_aborted: if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err) complete(&dev->cmd_complete); -- cgit v1.2.3-55-g7522