On Tue, Sep 16, 2025 at 10:02:59PM +0800, Shuai Zhang wrote:
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.
I'll leave having the changelog inside the commit message to the maintainer's discretion.
Otherwise:
Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com
Signed-off-by: Shuai Zhang quic_shuaz@quicinc.com
drivers/bluetooth/hci_qca.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)