releases/4.16.4/hid-input-fix-battery-level-reporting-on-bt-mice.patch

   1 From 2e210bbb7429cdcf1a1a3ad00c1bf98bd9bf2452 Mon Sep 17 00:00:00 2001
   2 From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
   3 Date: Tue, 3 Apr 2018 10:52:20 -0700
   4 Subject: HID: input: fix battery level reporting on BT mice
   5
   6 From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
   7
   8 commit 2e210bbb7429cdcf1a1a3ad00c1bf98bd9bf2452 upstream.
   9
  10 The commit 581c4484769e ("HID: input: map digitizer battery usage")
  11 assumed that devices having input (qas opposed to feature) report for
  12 battery strength would report the data on their own, without the need to
  13 be polled by the kernel; unfortunately it is not so. Many wireless mice
  14 do not send unsolicited reports with battery strength data and have to
  15 be polled explicitly. As a complication, stylus devices on digitizers
  16 are not normally connected to the base and thus can not be polled - the
  17 base can only determine battery strength in the stylus when it is in
  18 proximity.
  19
  20 To solve this issue, we add a special flag that tells the kernel
  21 to avoid polling the device (and expect unsolicited reports) and set it
  22 when report field with physical usage of digitizer stylus (HID_DG_STYLUS).
  23 Unless this flag is set, and we have not seen the unsolicited reports,
  24 the kernel will attempt to poll the device when userspace attempts to
  25 read "capacity" and "state" attributes of power_supply object
  26 corresponding to the devices battery.
  27
  28 Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
  29 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198095
  30 Cc: stable@vger.kernel.org
  31 Reported-and-tested-by: Martin van Es <martin@mrvanes.com>
  32 Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
  33 Signed-off-by: Jiri Kosina <jkosina@suse.cz>
  34 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  35
  36 ---
  37  drivers/hid/hid-input.c |   24 +++++++++++++++++-------
  38  include/linux/hid.h     |    9 ++++++++-
  39  2 files changed, 25 insertions(+), 8 deletions(-)
  40
  41 --- a/drivers/hid/hid-input.c
  42 +++ b/drivers/hid/hid-input.c
  43 @@ -387,7 +387,8 @@ static int hidinput_get_battery_property
  44                 break;
  45
  46         case POWER_SUPPLY_PROP_CAPACITY:
  47 -               if (dev->battery_report_type == HID_FEATURE_REPORT) {
  48 +               if (dev->battery_status != HID_BATTERY_REPORTED &&
  49 +                   !dev->battery_avoid_query) {
  50                         value = hidinput_query_battery_capacity(dev);
  51                         if (value < 0)
  52                                 return value;
  53 @@ -403,17 +404,17 @@ static int hidinput_get_battery_property
  54                 break;
  55
  56         case POWER_SUPPLY_PROP_STATUS:
  57 -               if (!dev->battery_reported &&
  58 -                   dev->battery_report_type == HID_FEATURE_REPORT) {
  59 +               if (dev->battery_status != HID_BATTERY_REPORTED &&
  60 +                   !dev->battery_avoid_query) {
  61                         value = hidinput_query_battery_capacity(dev);
  62                         if (value < 0)
  63                                 return value;
  64
  65                         dev->battery_capacity = value;
  66 -                       dev->battery_reported = true;
  67 +                       dev->battery_status = HID_BATTERY_QUERIED;
  68                 }
  69
  70 -               if (!dev->battery_reported)
  71 +               if (dev->battery_status == HID_BATTERY_UNKNOWN)
  72                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
  73                 else if (dev->battery_capacity == 100)
  74                         val->intval = POWER_SUPPLY_STATUS_FULL;
  75 @@ -486,6 +487,14 @@ static int hidinput_setup_battery(struct
  76         dev->battery_report_type = report_type;
  77         dev->battery_report_id = field->report->id;
  78
  79 +       /*
  80 +        * Stylus is normally not connected to the device and thus we
  81 +        * can't query the device and get meaningful battery strength.
  82 +        * We have to wait for the device to report it on its own.
  83 +        */
  84 +       dev->battery_avoid_query = report_type == HID_INPUT_REPORT &&
  85 +                                  field->physical == HID_DG_STYLUS;
  86 +
  87         dev->battery = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
  88         if (IS_ERR(dev->battery)) {
  89                 error = PTR_ERR(dev->battery);
  90 @@ -530,9 +539,10 @@ static void hidinput_update_battery(stru
  91
  92         capacity = hidinput_scale_battery_capacity(dev, value);
  93
  94 -       if (!dev->battery_reported || capacity != dev->battery_capacity) {
  95 +       if (dev->battery_status != HID_BATTERY_REPORTED ||
  96 +           capacity != dev->battery_capacity) {
  97                 dev->battery_capacity = capacity;
  98 -               dev->battery_reported = true;
  99 +               dev->battery_status = HID_BATTERY_REPORTED;
 100                 power_supply_changed(dev->battery);
 101         }
 102  }
 103 --- a/include/linux/hid.h
 104 +++ b/include/linux/hid.h
 105 @@ -515,6 +515,12 @@ enum hid_type {
 106         HID_TYPE_USBNONE
 107  };
 108
 109 +enum hid_battery_status {
 110 +       HID_BATTERY_UNKNOWN = 0,
 111 +       HID_BATTERY_QUERIED,            /* Kernel explicitly queried battery strength */
 112 +       HID_BATTERY_REPORTED,           /* Device sent unsolicited battery strength report */
 113 +};
 114 +
 115  struct hid_driver;
 116  struct hid_ll_driver;
 117
 118 @@ -557,7 +563,8 @@ struct hid_device {                                                 /* device repo
 119         __s32 battery_max;
 120         __s32 battery_report_type;
 121         __s32 battery_report_id;
 122 -       bool battery_reported;
 123 +       enum hid_battery_status battery_status;
 124 +       bool battery_avoid_query;
 125  #endif
 126
 127         unsigned int status;                                            /* see STAT flags above */