releases/4.9.68/i2c-i2c-cadence-initialize-configuration-before-probing-devices.patch

   1 From foo@baz Wed Dec  6 17:39:55 CET 2017
   2 From: Mike Looijmans <mike.looijmans@topic.nl>
   3 Date: Mon, 16 Jan 2017 15:49:38 +0100
   4 Subject: i2c: i2c-cadence: Initialize configuration before probing devices
   5
   6 From: Mike Looijmans <mike.looijmans@topic.nl>
   7
   8
   9 [ Upstream commit 0e1929dedea36781e25902118c93edd8d8f09af1 ]
  10
  11 The cadence I2C driver calls cdns_i2c_writereg(..) to setup a workaround
  12 in the controller, but did so after calling i2c_add_adapter() which starts
  13 probing devices on the bus. Change the order so that the configuration is
  14 completely finished before using the adapter.
  15
  16 Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
  17 Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
  18 Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20 ---
  21  drivers/i2c/busses/i2c-cadence.c |    8 ++++----
  22  1 file changed, 4 insertions(+), 4 deletions(-)
  23
  24 --- a/drivers/i2c/busses/i2c-cadence.c
  25 +++ b/drivers/i2c/busses/i2c-cadence.c
  26 @@ -962,10 +962,6 @@ static int cdns_i2c_probe(struct platfor
  27                 goto err_clk_dis;
  28         }
  29
  30 -       ret = i2c_add_adapter(&id->adap);
  31 -       if (ret < 0)
  32 -               goto err_clk_dis;
  33 -
  34         /*
  35          * Cadence I2C controller has a bug wherein it generates
  36          * invalid read transaction after HW timeout in master receiver mode.
  37 @@ -975,6 +971,10 @@ static int cdns_i2c_probe(struct platfor
  38          */
  39         cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);
  40
  41 +       ret = i2c_add_adapter(&id->adap);
  42 +       if (ret < 0)
  43 +               goto err_clk_dis;
  44 +
  45         dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n",
  46                  id->i2c_clk / 1000, (unsigned long)r_mem->start, id->irq);
  47