On QCS9075 and QCA8275 platforms, the BT_EN pin is always pulled up by hw and cannot be controlled by the host. As a result, in case of a firmware crash, the host cannot trigger a cold reset. Instead, the BT controller performs a warm restart on its own, without reloading the firmware.

This leads to the controller remaining in IBS_WAKE state, while the host expects it to be in sleep mode. The mismatch causes HCI reset commands to time out. Additionally, the driver does not clear internal flags QCA_SSR_TRIGGERED and QCA_IBS_DISABLED, which blocks the reset sequence. If the SSR duration exceeds 2 seconds, the host may enter TX sleep mode due to tx_idle_timeout, further preventing recovery. Also, memcoredump_flag is not cleared, so only the first SSR generates a coredump.

Tell driver that BT controller has undergone a proper restart sequence:

- Clear QCA_SSR_TRIGGERED and QCA_IBS_DISABLED flags after SSR. - Add a 50ms delay to allow the controller to complete its warm reset. - Reset tx_idle_timer to prevent the host from entering TX sleep mode. - Clear memcoredump_flag to allow multiple coredump captures.

Apply these steps only when HCI_QUIRK_NON_PERSISTENT_SETUP is not set, which indicates that BT_EN is defined in DTS and cannot be toggled.

Refer to the comment in include/net/bluetooth/hci.h for details on HCI_QUIRK_NON_PERSISTENT_SETUP.

Changes in v12: - Rewrote commit to clarify the actual issue and affected platforms. - Used imperative language to describe the fix. - Explained the role of HCI_QUIRK_NON_PERSISTENT_SETUP.

Signed-off-by: Shuai Zhang quic_shuaz@quicinc.com --- drivers/bluetooth/hci_qca.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index 4cff4d9be..2d6560482 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -1653,6 +1653,39 @@ static void qca_hw_error(struct hci_dev *hdev, u8 code) skb_queue_purge(&qca->rx_memdump_q); }

+ /* + * If the BT chip's bt_en pin is connected to a 3.3V power supply via + * hardware and always stays high, driver cannot control the bt_en pin. + * As a result, during SSR (SubSystem Restart), QCA_SSR_TRIGGERED and + * QCA_IBS_DISABLED flags cannot be cleared, which leads to a reset + * command timeout. + * Add an msleep delay to ensure controller completes the SSR process. + * + * Host will not download the firmware after SSR, controller to remain + * in the IBS_WAKE state, and the host needs to synchronize with it + * + * Since the bluetooth chip has been reset, clear the memdump state. + */ + if (!hci_test_quirk(hu->hdev, HCI_QUIRK_NON_PERSISTENT_SETUP)) { + /* + * When the SSR (SubSystem Restart) duration exceeds 2 seconds, + * it triggers host tx_idle_delay, which sets host TX state + * to sleep. Reset tx_idle_timer after SSR to prevent + * host enter TX IBS_Sleep mode. + */ + mod_timer(&qca->tx_idle_timer, jiffies + + msecs_to_jiffies(qca->tx_idle_delay)); + + /* Controller reset completion time is 50ms */ + msleep(50); + + clear_bit(QCA_SSR_TRIGGERED, &qca->flags); + clear_bit(QCA_IBS_DISABLED, &qca->flags); + + qca->tx_ibs_state = HCI_IBS_TX_AWAKE; + qca->memdump_state = QCA_MEMDUMP_IDLE; + } + clear_bit(QCA_HW_ERROR_EVENT, &qca->flags); }