[PATCH 4.9 075/109] i2c: i2c-cadence: Initialize configuration before probing devices

From: Greg Kroah-Hartman
Date: Thu Dec 07 2017 - 08:56:01 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mike Looijmans <mike.looijmans@xxxxxxxx>


[ Upstream commit 0e1929dedea36781e25902118c93edd8d8f09af1 ]

The cadence I2C driver calls cdns_i2c_writereg(..) to setup a workaround
in the controller, but did so after calling i2c_add_adapter() which starts
probing devices on the bus. Change the order so that the configuration is
completely finished before using the adapter.

Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-cadence.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -962,10 +962,6 @@ static int cdns_i2c_probe(struct platfor
goto err_clk_dis;
}

- ret = i2c_add_adapter(&id->adap);
- if (ret < 0)
- goto err_clk_dis;
-
/*
* Cadence I2C controller has a bug wherein it generates
* invalid read transaction after HW timeout in master receiver mode.
@@ -975,6 +971,10 @@ static int cdns_i2c_probe(struct platfor
*/
cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);

+ ret = i2c_add_adapter(&id->adap);
+ if (ret < 0)
+ goto err_clk_dis;
+
dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n",
id->i2c_clk / 1000, (unsigned long)r_mem->start, id->irq);