diff options
Diffstat (limited to 'libre/linux-libre-pae/0002-Bluetooth-btusb-check-conditions-before-enabling-USB.patch')
| -rw-r--r-- | libre/linux-libre-pae/0002-Bluetooth-btusb-check-conditions-before-enabling-USB.patch | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/libre/linux-libre-pae/0002-Bluetooth-btusb-check-conditions-before-enabling-USB.patch b/libre/linux-libre-pae/0002-Bluetooth-btusb-check-conditions-before-enabling-USB.patch new file mode 100644 index 000000000..574623ce2 --- /dev/null +++ b/libre/linux-libre-pae/0002-Bluetooth-btusb-check-conditions-before-enabling-USB.patch @@ -0,0 +1,85 @@ +From bdb12383a58d6989a0b1c2f925890948146bbc90 Mon Sep 17 00:00:00 2001 +From: Pauli Virtanen <pav@iki.fi> +Date: Mon, 26 Jul 2021 21:02:06 +0300 +Subject: [PATCH 2/2] Bluetooth: btusb: check conditions before enabling USB + ALT 3 for WBS +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Some USB BT adapters don't satisfy the MTU requirement mentioned in +commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS") +and have ALT 3 setting that produces no/garbled audio. Some adapters +with larger MTU were also reported to have problems with ALT 3. + +Add a flag and check it and MTU before selecting ALT 3, falling back to +ALT 1. Enable the flag for Realtek, restoring the previous behavior for +non-Realtek devices. + +Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1 +works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3 +works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling +ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad +audio) Intel 8087:0a2b. + +Signed-off-by: Pauli Virtanen <pav@iki.fi> +Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS") +Tested-by: Michał Kępień <kernel@kempniu.pl> + +Fixes: https://bugs.archlinux.org/task/71567 +--- + drivers/bluetooth/btusb.c | 22 ++++++++++++++-------- + 1 file changed, 14 insertions(+), 8 deletions(-) + +diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c +index 6d23308119d1..e8062d0b7d4d 100644 +--- a/drivers/bluetooth/btusb.c ++++ b/drivers/bluetooth/btusb.c +@@ -516,6 +516,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = { + #define BTUSB_HW_RESET_ACTIVE 12 + #define BTUSB_TX_WAIT_VND_EVT 13 + #define BTUSB_WAKEUP_DISABLE 14 ++#define BTUSB_USE_ALT3_FOR_WBS 15 + + struct btusb_data { + struct hci_dev *hdev; +@@ -1748,16 +1749,20 @@ static void btusb_work(struct work_struct *work) + /* Bluetooth USB spec recommends alt 6 (63 bytes), but + * many adapters do not support it. Alt 1 appears to + * work for all adapters that do not have alt 6, and +- * which work with WBS at all. ++ * which work with WBS at all. Some devices prefer ++ * alt 3 (HCI payload >= 60 Bytes let air packet ++ * data satisfy 60 bytes), requiring ++ * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72 ++ * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1. + */ +- new_alts = btusb_find_altsetting(data, 6) ? 6 : 1; +- /* Because mSBC frames do not need to be aligned to the +- * SCO packet boundary. If support the Alt 3, use the +- * Alt 3 for HCI payload >= 60 Bytes let air packet +- * data satisfy 60 bytes. +- */ +- if (new_alts == 1 && btusb_find_altsetting(data, 3)) ++ if (btusb_find_altsetting(data, 6)) ++ new_alts = 6; ++ else if (test_bit(BTUSB_USE_ALT3_FOR_WBS, &data->flags) && ++ hdev->sco_mtu >= 72 && ++ btusb_find_altsetting(data, 3)) + new_alts = 3; ++ else ++ new_alts = 1; + } + + if (btusb_switch_alt_setting(hdev, new_alts) < 0) +@@ -4733,6 +4738,7 @@ static int btusb_probe(struct usb_interface *intf, + * (DEVICE_REMOTE_WAKEUP) + */ + set_bit(BTUSB_WAKEUP_DISABLE, &data->flags); ++ set_bit(BTUSB_USE_ALT3_FOR_WBS, &data->flags); + } + + if (!reset) +-- +2.32.0 + |