* [PATCH v13 1/1] Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw
2025-12-03 3:37 [PATCH v13 0/1] Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw Shuai Zhang
@ 2025-12-03 3:37 ` Shuai Zhang
2025-12-03 4:13 ` bluez.test.bot
2025-12-03 20:10 ` [PATCH v13 0/1] " patchwork-bot+bluetooth
1 sibling, 1 reply; 4+ messages in thread
From: Shuai Zhang @ 2025-12-03 3:37 UTC (permalink / raw)
To: Marcel Holtmann, Luiz Augusto von Dentz
Cc: linux-arm-msm, linux-bluetooth, linux-kernel, cheng.jiang,
quic_chezhou, wei.deng, shuai.zhang, Dmitry Baryshkov
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:
- 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.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.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);
}
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v13 0/1] Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw
2025-12-03 3:37 [PATCH v13 0/1] Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw Shuai Zhang
2025-12-03 3:37 ` [PATCH v13 1/1] " Shuai Zhang
@ 2025-12-03 20:10 ` patchwork-bot+bluetooth
1 sibling, 0 replies; 4+ messages in thread
From: patchwork-bot+bluetooth @ 2025-12-03 20:10 UTC (permalink / raw)
To: Shuai Zhang
Cc: marcel, luiz.dentz, linux-arm-msm, linux-bluetooth, linux-kernel,
cheng.jiang, quic_chezhou, wei.deng
Hello:
This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:
On Wed, 3 Dec 2025 11:37:11 +0800 you wrote:
> Changes in v13:
> - Resending only to trigger CI, no code changes.
> - V12 Link
> https://lore.kernel.org/all/20250916140259.400285-1-quic_shuaz@quicinc.com/
>
> Shuai Zhang (1):
> Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is
> pulled up by hw
>
> [...]
Here is the summary with links:
- [v13,1/1] Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw
https://git.kernel.org/bluetooth/bluetooth-next/c/4746e2cd0e18
You are awesome, thank you!
--
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^ permalink raw reply [flat|nested] 4+ messages in thread