linux/net/bluetooth
João Paulo Rechi Vita f80c5dad7b Bluetooth: Ignore CC events not matching the last HCI command
This commit makes the kernel not send the next queued HCI command until
a command complete arrives for the last HCI command sent to the
controller. This change avoids a problem with some buggy controllers
(seen on two SKUs of QCA9377) that send an extra command complete event
for the previous command after the kernel had already sent a new HCI
command to the controller.

The problem was reproduced when starting an active scanning procedure,
where an extra command complete event arrives for the LE_SET_RANDOM_ADDR
command. When this happends the kernel ends up not processing the
command complete for the following commmand, LE_SET_SCAN_PARAM, and
ultimately behaving as if a passive scanning procedure was being
performed, when in fact controller is performing an active scanning
procedure. This makes it impossible to discover BLE devices as no device
found events are sent to userspace.

This problem is reproducible on 100% of the attempts on the affected
controllers. The extra command complete event can be seen at timestamp
27.420131 on the btmon logs bellow.

Bluetooth monitor ver 5.50
= Note: Linux version 5.0.0+ (x86_64)                                  0.352340
= Note: Bluetooth subsystem version 2.22                               0.352343
= New Index: 80:C5:F2:8F:87:84 (Primary,USB,hci0)               [hci0] 0.352344
= Open Index: 80:C5:F2:8F:87:84                                 [hci0] 0.352345
= Index Info: 80:C5:F2:8F:87:84 (Qualcomm)                      [hci0] 0.352346
@ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.352347
@ MGMT Open: btmon (privileged) version 1.14                  {0x0002} 0.352366
@ MGMT Open: btmgmt (privileged) version 1.14                {0x0003} 27.302164
@ MGMT Command: Start Discovery (0x0023) plen 1       {0x0003} [hci0] 27.302310
        Address type: 0x06
          LE Public
          LE Random
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6   #1 [hci0] 27.302496
        Address: 15:60:F2:91:B2:24 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4                 #2 [hci0] 27.419117
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7  #3 [hci0] 27.419244
        Type: Active (0x01)
        Interval: 11.250 msec (0x0012)
        Window: 11.250 msec (0x0012)
        Own address type: Random (0x01)
        Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 #4 [hci0] 27.420131
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2      #5 [hci0] 27.420259
        Scanning: Enabled (0x01)
        Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4                 #6 [hci0] 27.420969
      LE Set Scan Parameters (0x08|0x000b) ncmd 1
        Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 #7 [hci0] 27.421983
      LE Set Scan Enable (0x08|0x000c) ncmd 1
        Status: Success (0x00)
@ MGMT Event: Command Complete (0x0001) plen 4        {0x0003} [hci0] 27.422059
      Start Discovery (0x0023) plen 1
        Status: Success (0x00)
        Address type: 0x06
          LE Public
          LE Random
@ MGMT Event: Discovering (0x0013) plen 2             {0x0003} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0002} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0001} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2019-05-05 19:29:04 +02:00
..
bnep Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-10-25 12:48:22 -07:00
cmtp Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-10-25 12:48:22 -07:00
hidp Bluetooth: hidp: fix buffer overflow 2019-04-23 19:04:38 +02:00
rfcomm net: rework SIOCGSTAMP ioctl handling 2019-04-19 14:07:40 -07:00
6lowpan.c Bluetooth: 6lowpan: Fix debugfs_simple_attr.cocci warnings 2019-01-22 09:51:19 +01:00
Kconfig Revert "Bluetooth: Add option for disabling legacy ioctl interfaces" 2017-09-28 13:20:32 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
a2mp.c Bluetooth: a2mp: Use struct_size() helper 2019-02-18 14:01:59 +01:00
a2mp.h Bluetooth: Add BT_HS config option 2015-07-30 13:31:59 +02:00
af_bluetooth.c net: rework SIOCGSTAMP ioctl handling 2019-04-19 14:07:40 -07:00
amp.c Bluetooth: Use bt_dev_err and bt_dev_info when possible 2017-10-30 12:25:45 +02:00
amp.h Bluetooth: Add BT_HS config option 2015-07-30 13:31:59 +02:00
ecdh_helper.c Bluetooth: let the crypto subsystem generate the ecc privkey 2017-10-06 20:35:47 +02:00
ecdh_helper.h Bluetooth: let the crypto subsystem generate the ecc privkey 2017-10-06 20:35:47 +02:00
hci_conn.c Bluetooth: Align minimum encryption key size for LE and BR/EDR connections 2019-04-25 06:18:07 -07:00
hci_core.c Bluetooth: Ignore CC events not matching the last HCI command 2019-05-05 19:29:04 +02:00
hci_debugfs.c Bluetooth: Store Resolv list size 2018-07-06 12:40:08 +02:00
hci_debugfs.h Bluetooth: Provide option to enable/disable debugfs information 2015-02-15 18:54:13 +02:00
hci_event.c Bluetooth: Ignore CC events not matching the last HCI command 2019-05-05 19:29:04 +02:00
hci_request.c Bluetooth: Ignore CC events not matching the last HCI command 2019-05-05 19:29:04 +02:00
hci_request.h Bluetooth: Ignore CC events not matching the last HCI command 2019-05-05 19:29:04 +02:00
hci_sock.c Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2019-02-24 22:27:19 -08:00
hci_sysfs.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
l2cap_core.c Bluetooth: Fix not initializing L2CAP tx_credits 2019-04-23 18:09:07 +02:00
l2cap_sock.c Bluetooth: Add return check for L2CAP security level set 2019-04-23 18:09:07 +02:00
leds.c leds: triggers: let struct led_trigger::activate() return an error code 2018-07-05 23:21:10 +02:00
leds.h Bluetooth: Add combined LED trigger for controller power 2016-09-19 20:19:34 +02:00
lib.c Bluetooth: make baswap src const 2017-09-01 22:49:47 +02:00
mgmt.c Bluetooth: Use struct_size() helper 2019-04-23 19:31:05 +02:00
mgmt_util.c networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
mgmt_util.h Bluetooth: Add generic mgmt helper API 2015-03-17 18:03:08 +01:00
sco.c net: rework SIOCGSTAMP ioctl handling 2019-04-19 14:07:40 -07:00
selftest.c Bluetooth: Fix compiler warning with selftest duration calculation 2017-10-06 21:49:13 +03:00
selftest.h Bluetooth: Add support for self testing framework 2014-12-30 08:53:55 +02:00
smp.c crypto: drop mask=CRYPTO_ALG_ASYNC from 'shash' tfm allocations 2018-11-20 14:26:55 +08:00
smp.h Bluetooth: SMP: fix crash in unpairing 2018-09-26 12:39:32 +03:00