target/linux/bcm27xx/patches-5.10/950-0061-Fixes-a-problem-when-module-probes-before-i2c-module.patch

   1 From 4be98b29d123fc7615ea8404fbda450ec8acb084 Mon Sep 17 00:00:00 2001
   2 From: Joerg Schambacher <joerg@i2audio.com>
   3 Date: Fri, 16 Oct 2020 15:17:07 +0200
   4 Subject: [PATCH] Fixes a problem when module probes before i2c module
   5  is available
   6
   7 The driver crashed while a NULL pointer returned by i2c_get_adapter()
   8 has been used to access the i2c bus functions.
   9 The headphone probing function hb_hp_probe() now returns -EPROBE_DEFER
  10 in case the i2c module has not been loaded yet.
  11
  12 Signed-off-by: Joerg Schambacher <joerg@i2audio.com>
  13 ---
  14  sound/soc/bcm/hifiberry_dacplus.c | 9 +++++++--
  15  1 file changed, 7 insertions(+), 2 deletions(-)
  16
  17 --- a/sound/soc/bcm/hifiberry_dacplus.c
  18 +++ b/sound/soc/bcm/hifiberry_dacplus.c
  19 @@ -315,12 +315,14 @@ static int hb_hp_detect(void)
  20  {
  21         struct i2c_adapter *adap = i2c_get_adapter(1);
  22         int ret;
  23 -
  24         struct i2c_client tpa_i2c_client = {
  25                 .addr = 0x60,
  26                 .adapter = adap,
  27         };
  28
  29 +       if (!adap)
  30 +               return -EPROBE_DEFER;   /* I2C module not yet available */
  31 +
  32         ret = i2c_smbus_read_byte(&tpa_i2c_client) >= 0;
  33         i2c_put_adapter(adap);
  34         return ret;
  35 @@ -342,7 +344,10 @@ static int snd_rpi_hifiberry_dacplus_pro
  36         struct of_changeset ocs;
  37
  38         /* probe for head phone amp */
  39 -       if (hb_hp_detect()) {
  40 +       ret = hb_hp_detect();
  41 +       if (ret < 0)
  42 +               return ret;
  43 +       if (ret) {
  44                 card->aux_dev = hifiberry_dacplus_aux_devs;
  45                 card->num_aux_devs =
  46                                 ARRAY_SIZE(hifiberry_dacplus_aux_devs);