git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 165376f6b23e9a779850e750fb2eb06622e5a531 Mon Sep 17 00:00:00 2001
   2 From: RD Babiera <rdbabiera@google.com>
   3 Date: Thu, 29 Feb 2024 00:11:02 +0000
   4 Subject: usb: typec: altmodes/displayport: create sysfs nodes as driver's default device attribute group
   5
   6 From: RD Babiera <rdbabiera@google.com>
   7
   8 commit 165376f6b23e9a779850e750fb2eb06622e5a531 upstream.
   9
  10 The DisplayPort driver's sysfs nodes may be present to the userspace before
  11 typec_altmode_set_drvdata() completes in dp_altmode_probe. This means that
  12 a sysfs read can trigger a NULL pointer error by deferencing dp->hpd in
  13 hpd_show or dp->lock in pin_assignment_show, as dev_get_drvdata() returns
  14 NULL in those cases.
  15
  16 Remove manual sysfs node creation in favor of adding attribute group as
  17 default for devices bound to the driver. The ATTRIBUTE_GROUPS() macro is
  18 not used here otherwise the path to the sysfs nodes is no longer compliant
  19 with the ABI.
  20
  21 Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
  22 Cc: stable@vger.kernel.org
  23 Signed-off-by: RD Babiera <rdbabiera@google.com>
  24 Link: https://lore.kernel.org/r/20240229001101.3889432-2-rdbabiera@google.com
  25 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  26 ---
  27  drivers/usb/typec/altmodes/displayport.c |   18 +++++++++---------
  28  1 file changed, 9 insertions(+), 9 deletions(-)
  29
  30 --- a/drivers/usb/typec/altmodes/displayport.c
  31 +++ b/drivers/usb/typec/altmodes/displayport.c
  32 @@ -559,16 +559,21 @@ static ssize_t hpd_show(struct device *d
  33  }
  34  static DEVICE_ATTR_RO(hpd);
  35
  36 -static struct attribute *dp_altmode_attrs[] = {
  37 +static struct attribute *displayport_attrs[] = {
  38         &dev_attr_configuration.attr,
  39         &dev_attr_pin_assignment.attr,
  40         &dev_attr_hpd.attr,
  41         NULL
  42  };
  43
  44 -static const struct attribute_group dp_altmode_group = {
  45 +static const struct attribute_group displayport_group = {
  46         .name = "displayport",
  47 -       .attrs = dp_altmode_attrs,
  48 +       .attrs = displayport_attrs,
  49 +};
  50 +
  51 +static const struct attribute_group *displayport_groups[] = {
  52 +       &displayport_group,
  53 +       NULL,
  54  };
  55
  56  int dp_altmode_probe(struct typec_altmode *alt)
  57 @@ -576,7 +581,6 @@ int dp_altmode_probe(struct typec_altmod
  58         const struct typec_altmode *port = typec_altmode_get_partner(alt);
  59         struct fwnode_handle *fwnode;
  60         struct dp_altmode *dp;
  61 -       int ret;
  62
  63         /* FIXME: Port can only be DFP_U. */
  64
  65 @@ -587,10 +591,6 @@ int dp_altmode_probe(struct typec_altmod
  66               DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
  67                 return -ENODEV;
  68
  69 -       ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
  70 -       if (ret)
  71 -               return ret;
  72 -
  73         dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
  74         if (!dp)
  75                 return -ENOMEM;
  76 @@ -624,7 +624,6 @@ void dp_altmode_remove(struct typec_altm
  77  {
  78         struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
  79
  80 -       sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
  81         cancel_work_sync(&dp->work);
  82
  83         if (dp->connector_fwnode) {
  84 @@ -649,6 +648,7 @@ static struct typec_altmode_driver dp_al
  85         .driver = {
  86                 .name = "typec_displayport",
  87                 .owner = THIS_MODULE,
  88 +               .dev_groups = displayport_groups,
  89         },
  90  };
  91  module_typec_altmode_driver(dp_altmode_driver);