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authorShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>2019-02-05 16:42:53 +0530
committerWolfram Sang <wsa@the-dreams.de>2019-02-15 09:42:17 +0100
commitd358def706880defa4c9e87381c5bf086a97d5f9 (patch)
tree9b4bb7c99fa280365631179c3d71a44d2fd90369
parentd13937116f1e82bf508a6325111b322c30c85eb9 (diff)
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>
-rw-r--r--drivers/i2c/busses/i2c-cadence.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b13605718291..d917cefc5a19 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. */