[PATCH] Bluetooth: Add quirk to ignore reserved PHY bits in LE Extended Adv Report

[PATCH] Bluetooth: Add quirk to ignore reserved PHY bits in LE Extended Adv Report

[Sven Peter via B4 Relay]

From: Sven Peter <sven@svenpeter.dev>

Some Broadcom controllers found on Apple Silicon machines abuse the
reserved bits inside the PHY fields of LE Extended Advertising Report
events for additional flags. Add a quirk to drop these and correctly
extract the Primary/Secondary_PHY field.

The following excerpt from a btmon trace shows a report received with
"Reserved" for "Primary PHY" on a 4388 controller:

> HCI Event: LE Meta Event (0x3e) plen 26
      LE Extended Advertising Report (0x0d)
        Num reports: 1
        Entry 0
          Event type: 0x2515
            Props: 0x0015
              Connectable
              Directed
              Use legacy advertising PDUs
            Data status: Complete
            Reserved (0x2500)
         Legacy PDU Type: Reserved (0x2515)
          Address type: Random (0x01)
          Address: 00:00:00:00:00:00 (Static)
          Primary PHY: Reserved
          Secondary PHY: No packets
          SID: no ADI field (0xff)
          TX power: 127 dBm
          RSSI: -60 dBm (0xc4)
          Periodic advertising interval: 0.00 msec (0x0000)
          Direct address type: Public (0x00)
          Direct address: 00:00:00:00:00:00 (Apple, Inc.)
          Data length: 0x00

Cc: stable@vger.kernel.org
Fixes: 2e7ed5f5e69b ("Bluetooth: hci_sync: Use advertised PHYs on hci_le_ext_create_conn_sync")
Reported-by: Janne Grunau <j@jannau.net>
Closes: https://lore.kernel.org/all/Zjz0atzRhFykROM9@robin
Tested-by: Janne Grunau <j@jannau.net>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
 drivers/bluetooth/hci_bcm4377.c |  8 ++++++++
 include/net/bluetooth/hci.h     | 11 +++++++++++
 net/bluetooth/hci_event.c       |  7 +++++++
 3 files changed, 26 insertions(+)

diff --git a/drivers/bluetooth/hci_bcm4377.c b/drivers/bluetooth/hci_bcm4377.c
index 9a7243d5db71..55109ad45115 100644
--- a/drivers/bluetooth/hci_bcm4377.c
+++ b/drivers/bluetooth/hci_bcm4377.c
@@ -495,6 +495,10 @@ struct bcm4377_data;
  *                  extended scanning
  * broken_mws_transport_config: Set to true if the chip erroneously claims to
  *                              support MWS Transport Configuration
+ * broken_le_ext_adv_report_phy: Set to true if this chip stuffs flags inside
+ *                               reserved bits of Primary/Secondary_PHY inside
+ *                               LE Extended Advertising Report events which
+ *                               have to be ignored
  * send_calibration: Optional callback to send calibration data
  * send_ptb: Callback to send "PTB" regulatory/calibration data
  */
@@ -513,6 +517,7 @@ struct bcm4377_hw {
 	unsigned long broken_ext_scan : 1;
 	unsigned long broken_mws_transport_config : 1;
 	unsigned long broken_le_coded : 1;
+	unsigned long broken_le_ext_adv_report_phy : 1;
 
 	int (*send_calibration)(struct bcm4377_data *bcm4377);
 	int (*send_ptb)(struct bcm4377_data *bcm4377,
@@ -2374,6 +2379,8 @@ static int bcm4377_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		set_bit(HCI_QUIRK_BROKEN_EXT_SCAN, &hdev->quirks);
 	if (bcm4377->hw->broken_le_coded)
 		set_bit(HCI_QUIRK_BROKEN_LE_CODED, &hdev->quirks);
+	if (bcm4377->hw->broken_le_ext_adv_report_phy)
+		set_bit(HCI_QUIRK_FIXUP_LE_EXT_ADV_REPORT_PHY, &hdev->quirks);
 
 	pci_set_drvdata(pdev, bcm4377);
 	hci_set_drvdata(hdev, bcm4377);
@@ -2478,6 +2485,7 @@ static const struct bcm4377_hw bcm4377_hw_variants[] = {
 		.clear_pciecfg_subsystem_ctrl_bit19 = true,
 		.broken_mws_transport_config = true,
 		.broken_le_coded = true,
+		.broken_le_ext_adv_report_phy = true,
 		.send_calibration = bcm4387_send_calibration,
 		.send_ptb = bcm4378_send_ptb,
 	},
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 5c12761cbc0e..342aab86dad6 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -347,6 +347,17 @@ enum {
 	 * claim to support it.
 	 */
 	HCI_QUIRK_BROKEN_READ_ENC_KEY_SIZE,
+
+	/*
+	 * When this quirk is set, the reserved bits of Primary/Secondary_PHY
+	 * inside the LE Extended Advertising Report events are discarded.
+	 * This is required for some Apple/Broadcom controllers which
+	 * abuse these reserved bits for unrelated flags.
+	 *
+	 * This quirk can be set before hci_register_dev is called or
+	 * during the hdev->setup vendor callback.
+	 */
+	HCI_QUIRK_FIXUP_LE_EXT_ADV_REPORT_PHY,
 };
 
 /* HCI device flags */
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d72d238c1656..01d3a8d343f1 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -6446,6 +6446,13 @@ static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, void *data,
 
 		evt_type = __le16_to_cpu(info->type) & LE_EXT_ADV_EVT_TYPE_MASK;
 		legacy_evt_type = ext_evt_type_to_legacy(hdev, evt_type);
+
+		if (test_bit(HCI_QUIRK_FIXUP_LE_EXT_ADV_REPORT_PHY,
+			     &hdev->quirks)) {
+			info->primary_phy &= 0x1f;
+			info->secondary_phy &= 0x1f;
+		}
+
 		if (legacy_evt_type != LE_ADV_INVALID) {
 			process_adv_report(hdev, legacy_evt_type, &info->bdaddr,
 					   info->bdaddr_type, NULL, 0,

---
base-commit: a38297e3fb012ddfa7ce0321a7e5a8daeb1872b6
change-id: 20240512-btfix-95c10c456f17

Best regards,
-- 
Sven Peter <sven@svenpeter.dev>

RE: Bluetooth: Add quirk to ignore reserved PHY bits in LE Extended Adv Report

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2682 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=853484

---Test result---

Test Summary:
CheckPatch                    PASS      1.40 seconds
GitLint                       PASS      0.31 seconds
SubjectPrefix                 PASS      0.12 seconds
BuildKernel                   PASS      30.33 seconds
CheckAllWarning               PASS      32.73 seconds
CheckSparse                   WARNING   38.91 seconds
CheckSmatch                   FAIL      36.29 seconds
BuildKernel32                 PASS      30.33 seconds
TestRunnerSetup               PASS      527.22 seconds
TestRunner_l2cap-tester       PASS      20.31 seconds
TestRunner_iso-tester         PASS      32.81 seconds
TestRunner_bnep-tester        PASS      4.73 seconds
TestRunner_mgmt-tester        PASS      113.89 seconds
TestRunner_rfcomm-tester      PASS      7.28 seconds
TestRunner_sco-tester         PASS      16.93 seconds
TestRunner_ioctl-tester       PASS      7.83 seconds
TestRunner_mesh-tester        PASS      5.99 seconds
TestRunner_smp-tester         PASS      6.93 seconds
TestRunner_userchan-tester    PASS      5.03 seconds
IncrementalBuild              PASS      28.40 seconds

Details
##############################
Test: CheckSparse - WARNING
Desc: Run sparse tool with linux kernel
Output:
net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):
##############################
Test: CheckSmatch - FAIL
Desc: Run smatch tool with source
Output:

Segmentation fault (core dumped)
make[4]: *** [scripts/Makefile.build:244: net/bluetooth/hci_core.o] Error 139
make[4]: *** Deleting file 'net/bluetooth/hci_core.o'
make[3]: *** [scripts/Makefile.build:485: net/bluetooth] Error 2
make[2]: *** [scripts/Makefile.build:485: net] Error 2
make[2]: *** Waiting for unfinished jobs....
Segmentation fault (core dumped)
make[4]: *** [scripts/Makefile.build:244: drivers/bluetooth/bcm203x.o] Error 139
make[4]: *** Deleting file 'drivers/bluetooth/bcm203x.o'
make[4]: *** Waiting for unfinished jobs....
Segmentation fault (core dumped)
make[4]: *** [scripts/Makefile.build:244: drivers/bluetooth/bpa10x.o] Error 139
make[4]: *** Deleting file 'drivers/bluetooth/bpa10x.o'
make[3]: *** [scripts/Makefile.build:485: drivers/bluetooth] Error 2
make[2]: *** [scripts/Makefile.build:485: drivers] Error 2
make[1]: *** [/github/workspace/src/src/Makefile:1919: .] Error 2
make: *** [Makefile:240: __sub-make] Error 2


---
Regards,
Linux Bluetooth

Re: [PATCH] Bluetooth: Add quirk to ignore reserved PHY bits in LE Extended Adv Report

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Wed, 15 May 2024 18:02:58 +0000 you wrote:
> From: Sven Peter <sven@svenpeter.dev>
> 
> Some Broadcom controllers found on Apple Silicon machines abuse the
> reserved bits inside the PHY fields of LE Extended Advertising Report
> events for additional flags. Add a quirk to drop these and correctly
> extract the Primary/Secondary_PHY field.
> 
> [...]

Here is the summary with links:
  - Bluetooth: Add quirk to ignore reserved PHY bits in LE Extended Adv Report
    https://git.kernel.org/bluetooth/bluetooth-next/c/9dc8ac15ca51

You are awesome, thank you!
-- 
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