linux/include
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
..
acpi ACPI: use different default debug value than ACPICA 2019-03-25 10:45:59 +01:00
asm-generic syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
clocksource
crypto
drm drm/ttm: fix re-init of global structures 2019-04-19 11:11:20 -05:00
dt-bindings dt-bindings: clock: sifive: add FU540-C000 PRCI clock constants 2019-04-09 20:36:40 -07:00
keys KEYS: trusted: fix -Wvarags warning 2019-04-08 15:58:54 -07:00
kvm ARM: some cleanups, direct physical timer assignment, cache sanitization 2019-03-15 15:00:28 -07:00
linux Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-02 22:14:21 -04:00
math-emu
media media: include: fix several typos 2019-03-01 09:45:52 -05:00
memory
misc auxdisplay: charlcd: Introduce charlcd_free() helper 2019-03-17 08:48:16 +01:00
net Bluetooth: Ignore CC events not matching the last HCI command 2019-05-05 19:29:04 +02:00
pcmcia
ras
rdma
scsi scsi: kill command serial number 2019-02-27 09:19:24 -05:00
soc IOMMU Updates for Linux v5.1 2019-03-10 12:29:52 -07:00
sound ASoC: core: conditionally increase module refcount on component open 2019-04-08 14:15:44 +07:00
target
trace selftests: bpf: test writable buffers in raw tps 2019-04-26 19:04:19 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-02 22:14:21 -04:00
video media updates for v5.1-rc1 2019-03-09 14:45:54 -08:00
xen