[PATCH] Bluetooth: Add Broadcom channel priority commands

[Sasha Finkelstein via B4 Relay <devnull+fnkl.kernel.gmail.com@kernel.org>]

From: Sasha Finkelstein <fnkl.kernel@gmail.com>

Certain Broadcom bluetooth chips (bcm4377/bcm4378/bcm438) need ACL
streams carrying audio to be set as "high priority" using a vendor
specific command to prevent 10-ish second-long dropouts whenever
something does a device scan. This series adds an ioctl to control
the priorities and hooks it up for the relevant chips.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 MAINTAINERS                      |  2 ++
 drivers/bluetooth/hci_bcm4377.c  |  2 ++
 include/net/bluetooth/hci_core.h | 12 ++++++++++++
 include/net/bluetooth/hci_sock.h |  7 +++++++
 net/bluetooth/Kconfig            |  7 +++++++
 net/bluetooth/Makefile           |  1 +
 net/bluetooth/brcm.c             | 29 +++++++++++++++++++++++++++++
 net/bluetooth/brcm.h             | 17 +++++++++++++++++
 net/bluetooth/hci_conn.c         | 11 +++++++++++
 net/bluetooth/hci_sock.c         |  4 ++++
 10 files changed, 92 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index c3fe46d7c4bc..81be021367ec 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2562,6 +2562,8 @@ F:	include/dt-bindings/pinctrl/apple.h
 F:	include/linux/mfd/macsmc.h
 F:	include/linux/soc/apple/*
 F:	include/uapi/drm/asahi_drm.h
+F:	net/bluetooth/brcm.c
+F:	net/bluetooth/brcm.h
 
 ARM/ARTPEC MACHINE SUPPORT
 M:	Jesper Nilsson <jesper.nilsson@axis.com>
diff --git a/drivers/bluetooth/hci_bcm4377.c b/drivers/bluetooth/hci_bcm4377.c
index 925d0a635945..5f79920c0306 100644
--- a/drivers/bluetooth/hci_bcm4377.c
+++ b/drivers/bluetooth/hci_bcm4377.c
@@ -2397,6 +2397,8 @@ static int bcm4377_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (bcm4377->hw->broken_le_ext_adv_report_phy)
 		hci_set_quirk(hdev, HCI_QUIRK_FIXUP_LE_EXT_ADV_REPORT_PHY);
 
+	hci_set_brcm_capable(hdev);
+
 	pci_set_drvdata(pdev, bcm4377);
 	hci_set_drvdata(hdev, bcm4377);
 	SET_HCIDEV_DEV(hdev, &pdev->dev);
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a7bffb908c1e..ef3b5433203c 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -642,6 +642,10 @@ struct hci_dev {
 	bool			aosp_quality_report;
 #endif
 
+#if IS_ENABLED(CONFIG_BT_BRCMEXT)
+	bool			brcm_capable;
+#endif
+
 	int (*open)(struct hci_dev *hdev);
 	int (*close)(struct hci_dev *hdev);
 	int (*flush)(struct hci_dev *hdev);
@@ -1791,6 +1795,13 @@ static inline void hci_set_aosp_capable(struct hci_dev *hdev)
 #endif
 }
 
+static inline void hci_set_brcm_capable(struct hci_dev *hdev)
+{
+#if IS_ENABLED(CONFIG_BT_BRCMEXT)
+	hdev->brcm_capable = true;
+#endif
+}
+
 static inline void hci_devcd_setup(struct hci_dev *hdev)
 {
 #ifdef CONFIG_DEV_COREDUMP
@@ -1812,6 +1823,7 @@ int hci_get_conn_list(void __user *arg);
 int hci_get_conn_info(struct hci_dev *hdev, void __user *arg);
 int hci_get_auth_info(struct hci_dev *hdev, void __user *arg);
 int hci_inquiry(void __user *arg);
+int hci_set_acl_prio(struct hci_dev *hdev, void __user *arg);
 
 struct bdaddr_list *hci_bdaddr_list_lookup(struct list_head *list,
 					   bdaddr_t *bdaddr, u8 type);
diff --git a/include/net/bluetooth/hci_sock.h b/include/net/bluetooth/hci_sock.h
index 13e8cd4414a1..95d156ac4cae 100644
--- a/include/net/bluetooth/hci_sock.h
+++ b/include/net/bluetooth/hci_sock.h
@@ -91,6 +91,8 @@ struct hci_ufilter {
 
 #define HCIINQUIRY	_IOR('H', 240, int)
 
+#define HCISETACLPRIO	_IOW('H', 250, int)
+
 /* Ioctl requests structures */
 struct hci_dev_stats {
 	__u32 err_rx;
@@ -171,6 +173,11 @@ struct hci_inquiry_req {
 	__u8  length;
 	__u8  num_rsp;
 };
+
+struct hci_acl_prio_req {
+	__u16 handle;
+	__u8  high_prio;
+};
 #define IREQ_CACHE_FLUSH 0x0001
 
 #endif /* __HCI_SOCK_H */
diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig
index 6b2b65a66700..0f2a5fbcafc5 100644
--- a/net/bluetooth/Kconfig
+++ b/net/bluetooth/Kconfig
@@ -110,6 +110,13 @@ config BT_AOSPEXT
 	  This options enables support for the Android Open Source
 	  Project defined HCI vendor extensions.
 
+config BT_BRCMEXT
+	bool "Enable Broadcom extensions"
+	depends on BT
+	help
+	  This option enables support for the Broadcom defined HCI
+	  vendor extensions.
+
 config BT_DEBUGFS
 	bool "Export Bluetooth internals in debugfs"
 	depends on BT && DEBUG_FS
diff --git a/net/bluetooth/Makefile b/net/bluetooth/Makefile
index a7eede7616d8..b4c9013a46ce 100644
--- a/net/bluetooth/Makefile
+++ b/net/bluetooth/Makefile
@@ -24,5 +24,6 @@ bluetooth-$(CONFIG_BT_LE) += iso.o
 bluetooth-$(CONFIG_BT_LEDS) += leds.o
 bluetooth-$(CONFIG_BT_MSFTEXT) += msft.o
 bluetooth-$(CONFIG_BT_AOSPEXT) += aosp.o
+bluetooth-$(CONFIG_BT_BRCMEXT) += brcm.o
 bluetooth-$(CONFIG_BT_DEBUGFS) += hci_debugfs.o
 bluetooth-$(CONFIG_BT_SELFTEST) += selftest.o
diff --git a/net/bluetooth/brcm.c b/net/bluetooth/brcm.c
new file mode 100644
index 000000000000..d03d2af5dc7e
--- /dev/null
+++ b/net/bluetooth/brcm.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 The Asahi Linux Contributors
+ */
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "brcm.h"
+
+int brcm_set_high_priority(struct hci_dev *hdev, u16 handle, bool enable)
+{
+	struct sk_buff *skb;
+	u8 cmd[3];
+
+	if (!hdev->brcm_capable)
+		return -EOPNOTSUPP;
+
+	cmd[0] = handle;
+	cmd[1] = handle >> 8;
+	cmd[2] = !!enable;
+
+	skb = hci_cmd_sync(hdev, 0xfc57, sizeof(cmd), cmd, HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	kfree_skb(skb);
+	return 0;
+}
diff --git a/net/bluetooth/brcm.h b/net/bluetooth/brcm.h
new file mode 100644
index 000000000000..a501f2988a96
--- /dev/null
+++ b/net/bluetooth/brcm.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2026 The Asahi Linux Contributors
+ */
+
+#if IS_ENABLED(CONFIG_BT_BRCMEXT)
+
+int brcm_set_high_priority(struct hci_dev *hdev, u16 handle, bool enable);
+
+#else
+
+static inline int brcm_set_high_priority(struct hci_dev *hdev, u16 handle, bool enable)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 11d3ad8d2551..b2c7414a9c5b 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -35,6 +35,7 @@
 #include <net/bluetooth/iso.h>
 #include <net/bluetooth/mgmt.h>
 
+#include "brcm.h"
 #include "smp.h"
 #include "eir.h"
 
@@ -2775,6 +2776,16 @@ int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
 	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
 }
 
+int hci_set_acl_prio(struct hci_dev *hdev, void __user *arg)
+{
+	struct hci_acl_prio_req req;
+
+	if (copy_from_user(&req, arg, sizeof(req)))
+		return -EFAULT;
+
+	return brcm_set_high_priority(hdev, req.handle, req.high_prio);
+}
+
 struct hci_chan *hci_chan_create(struct hci_conn *conn)
 {
 	struct hci_dev *hdev = conn->hdev;
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 0290dea081f6..4be6aeeb6bad 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1035,6 +1035,9 @@ static int hci_sock_bound_ioctl(struct sock *sk, unsigned int cmd,
 		if (!capable(CAP_NET_ADMIN))
 			return -EPERM;
 		return hci_sock_reject_list_del(hdev, (void __user *)arg);
+
+	case HCISETACLPRIO:
+		return hci_set_acl_prio(hdev, (void __user *)arg);
 	}
 
 	return -ENOIOCTLCMD;
@@ -1072,6 +1075,7 @@ static int hci_sock_ioctl(struct socket *sock, unsigned int cmd,
 	case HCIGETAUTHINFO:
 	case HCIBLOCKADDR:
 	case HCIUNBLOCKADDR:
+	case HCISETACLPRIO:
 		break;
 	default:
 		return -ENOIOCTLCMD;

---
base-commit: bfe62a454542cfad3379f6ef5680b125f41e20f4
change-id: 20260407-brcm-prio-b630e6cc3834

Best regards,
-- 
Sasha Finkelstein <fnkl.kernel@gmail.com>