i2c: cadence: Fix the hold bit setting

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 <kyle.roeschley@ni.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Tested-by: Kyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b136057..d917cef 100644 (file)
--- 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. */