From 9f7ae2d5c74947dcf942e4c86e5c72bc84c42c6b Mon Sep 17 00:00:00 2001 From: Shubhrajyoti Datta Date: Tue, 5 Feb 2019 16:42:53 +0530 Subject: [PATCH] i2c: cadence: Fix the hold bit setting [ Upstream commit d358def706880defa4c9e87381c5bf086a97d5f9 ] In case the hold bit is not needed we are carrying the old values. Fix the same by resetting the bit when not needed. Fixes the sporadic i2c bus lockups on National Instruments Zynq-based devices. Fixes: df8eb5691c48 ("i2c: Add driver for Cadence I2C controller") Reported-by: Kyle Roeschley Acked-by: Michal Simek Signed-off-by: Shubhrajyoti Datta Tested-by: Kyle Roeschley Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-cadence.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c index 45d6771fac8c..59c08d5b75d6 100644 --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -382,8 +382,10 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id) * Check for the message size against FIFO depth and set the * 'hold bus' bit if it is greater than FIFO depth. */ - if (id->recv_count > CDNS_I2C_FIFO_DEPTH) + if ((id->recv_count > CDNS_I2C_FIFO_DEPTH) || id->bus_hold_flag) ctrl_reg |= CDNS_I2C_CR_HOLD; + else + ctrl_reg = ctrl_reg & ~CDNS_I2C_CR_HOLD; cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); @@ -440,8 +442,11 @@ static void cdns_i2c_msend(struct cdns_i2c *id) * Check for the message size against FIFO depth and set the * 'hold bus' bit if it is greater than FIFO depth. */ - if (id->send_count > CDNS_I2C_FIFO_DEPTH) + if ((id->send_count > CDNS_I2C_FIFO_DEPTH) || id->bus_hold_flag) ctrl_reg |= CDNS_I2C_CR_HOLD; + else + ctrl_reg = ctrl_reg & ~CDNS_I2C_CR_HOLD; + cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); /* Clear the interrupts in interrupt status register. */