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Bluetooth: Add quirk to disable extended scanning
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Broadcom 4377 controllers found in Apple x86 Macs with the T2 chip
claim to support extended scanning when querying supported states,

< HCI Command: LE Read Supported St.. (0x08|0x001c) plen 0  #27 [hci0] 2.971839
> HCI Event: Command Complete (0x0e) plen 12                #28 [hci0] 2.972730
      LE Read Supported States (0x08|0x001c) ncmd 1
        Status: Success (0x00)
        States: 0x000003ffffffffff
[...]
          LE Set Extended Scan Parameters (Octet 37 - Bit 5)
          LE Set Extended Scan Enable (Octet 37 - Bit 6)
[...]

, but then fail to actually implement the extended scanning:

< HCI Command: LE Set Extended Sca.. (0x08|0x0041) plen 8  #105 [hci0] 5.460776
        Own address type: Random (0x01)
        Filter policy: Accept all advertisement (0x00)
        PHYs: 0x01
        Entry 0: LE 1M
          Type: Active (0x01)
          Interval: 11.250 msec (0x0012)
          Window: 11.250 msec (0x0012)
> HCI Event: Command Complete (0x0e) plen 4                #106 [hci0] 5.461777
      LE Set Extended Scan Parameters (0x08|0x0041) ncmd 1
        Status: Unknown HCI Command (0x01)

Signed-off-by: Sven Peter <[email protected]>
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svenpeter42 committed Jul 25, 2022
1 parent 804203a commit c7fc2cd
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Showing 2 changed files with 13 additions and 1 deletion.
10 changes: 10 additions & 0 deletions include/net/bluetooth/hci.h
Original file line number Diff line number Diff line change
Expand Up @@ -285,6 +285,16 @@ enum {
* during the hdev->setup vendor callback.
*/
HCI_QUIRK_FIXUP_LE_EXT_ADV_REPORT_EVT_TYPE,

/*
* When this quirk is set, the HCI_OP_LE_SET_EXT_SCAN_ENABLE command is
* disabled. This is required for some Broadcom controllers which
* erroneously claim to support extended scanning.
*
* This quirk can be set before hci_register_dev is called or
* during the hdev->setup vendor callback.
*/
HCI_QUIRK_BROKEN_EXT_SCAN,
};

/* HCI device flags */
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4 changes: 3 additions & 1 deletion include/net/bluetooth/hci_core.h
Original file line number Diff line number Diff line change
Expand Up @@ -1501,7 +1501,9 @@ void hci_conn_del_sysfs(struct hci_conn *conn);

/* Use ext scanning if set ext scan param and ext scan enable is supported */
#define use_ext_scan(dev) (((dev)->commands[37] & 0x20) && \
((dev)->commands[37] & 0x40))
((dev)->commands[37] & 0x40) && \
!test_bit(HCI_QUIRK_BROKEN_EXT_SCAN, &(dev)->quirks))

/* Use ext create connection if command is supported */
#define use_ext_conn(dev) ((dev)->commands[37] & 0x80)

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