BACKPORT: driver: bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw #465
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…l when BT_EN is pulled up by hw 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 the 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. Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.com> Link: https://lore.kernel.org/all/20251203033712.446632-1-shuai.zhang@oss.qualcomm.com/
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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 the driver that the BT controller has undergone a proper restart sequence:
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.
CRs-Fixed: <4251424>
Link: https://lore.kernel.org/all/20251203033712.446632-1-shuai.zhang@oss.qualcomm.com/