On Wed, Jul 23, 2025 at 07:27:15PM GMT, Kiran K wrote:
> From: Chandrashekar Devegowda <chandrashekar.devegowda@xxxxxxxxx>
>
> This patch implements _suspend() and _resume() functions for the
> Bluetooth controller. When the system enters a suspended state, the
> driver notifies the controller to perform necessary housekeeping tasks
> by writing to the sleep control register and waits for an alive
> interrupt. The firmware raises the alive interrupt when it has
> transitioned to the D3 state. The same flow occurs when the system
> resumes.
>
> Command to test host initiated wakeup after 60 seconds
> sudo rtcwake -m mem -s 60
>
> dmesg log (tested on Whale Peak2 on Panther Lake platform)
> On system suspend:
> [ 516.418316] Bluetooth: hci0: device entered into d3 state from d0 in 81 us
>
> On system resume:
> [ 542.174128] Bluetooth: hci0: device entered into d0 state from d3 in 357 us
>
> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@xxxxxxxxx>
> Signed-off-by: Kiran K <kiran.k@xxxxxxxxx>
> ---
> changes in v5:
> - Address review comments
>
> changes in v4:
> - Moved document and section details from the commit message as comment in code.
>
> changes in v3:
> - Corrected the typo's
> - Updated the CC list as suggested.
> - Corrected the format specifiers in the logs.
>
> changes in v2:
> - Updated the commit message with test steps and logs.
> - Added logs to include the timeout message.
> - Fixed a potential race condition during suspend and resume.
>
> drivers/bluetooth/btintel_pcie.c | 102 +++++++++++++++++++++++++++++++
> drivers/bluetooth/btintel_pcie.h | 4 ++
> 2 files changed, 106 insertions(+)
>
> diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
> index 6e7bbbd35279..a96975a55cbe 100644
> --- a/drivers/bluetooth/btintel_pcie.c
> +++ b/drivers/bluetooth/btintel_pcie.c
> @@ -540,6 +540,12 @@ static int btintel_pcie_reset_bt(struct btintel_pcie_data *data)
> return reg == 0 ? 0 : -ENODEV;
> }
>
> +static void btintel_pcie_set_persistence_mode(struct btintel_pcie_data *data)
> +{
> + btintel_pcie_set_reg_bits(data, BTINTEL_PCIE_CSR_HW_BOOT_CONFIG,
> + BTINTEL_PCIE_CSR_HW_BOOT_CONFIG_KEEP_ON);
> +}
> +
> static void btintel_pcie_mac_init(struct btintel_pcie_data *data)
> {
> u32 reg;
> @@ -829,6 +835,8 @@ static int btintel_pcie_enable_bt(struct btintel_pcie_data *data)
> */
> data->boot_stage_cache = 0x0;
>
> + btintel_pcie_set_persistence_mode(data);
> +
> /* Set MAC_INIT bit to start primary bootloader */
> reg = btintel_pcie_rd_reg32(data, BTINTEL_PCIE_CSR_FUNC_CTRL_REG);
> reg &= ~(BTINTEL_PCIE_CSR_FUNC_CTRL_FUNC_INIT |
> @@ -2573,11 +2581,105 @@ static void btintel_pcie_coredump(struct device *dev)
> }
> #endif
>
> +#ifdef CONFIG_PM
> +static int btintel_pcie_suspend_late(struct device *dev, pm_message_t mesg)
> +{
> + struct pci_dev *pdev = to_pci_dev(dev);
> + struct btintel_pcie_data *data;
> + ktime_t start;
> + u32 dxstate;
> + s64 delta;
> + int err;
> +
> + data = pci_get_drvdata(pdev);
> +
> + if (mesg.event == PM_EVENT_SUSPEND)
> + dxstate = BTINTEL_PCIE_STATE_D3_HOT;
> + else
> + dxstate = BTINTEL_PCIE_STATE_D3_COLD;
> +
> + data->gp0_received = false;
> +
> + start = ktime_get();
> +
> + /* Refer: 6.4.11.7 -> Platform power management */
> + btintel_pcie_wr_sleep_cntrl(data, dxstate);
> + err = wait_event_timeout(data->gp0_wait_q, data->gp0_received,
> + msecs_to_jiffies(BTINTEL_DEFAULT_INTR_TIMEOUT_MS));
> + delta = ktime_to_ns(ktime_get() - start) / 1000;
> +
> + if (err == 0) {
> + bt_dev_err(data->hdev, "Timeout (%u ms) on alive interrupt for D3 entry",
> + BTINTEL_DEFAULT_INTR_TIMEOUT_MS);
> + return -EBUSY;
> + }
> + bt_dev_info(data->hdev, "device entered into d3 state from d0 in %lld us",
> + delta);
> + return 0;
> +}
> +
> +static int btintel_pcie_suspend(struct device *dev)
> +{
> + return btintel_pcie_suspend_late(dev, PMSG_SUSPEND);
> +}
> +
> +static int btintel_pcie_hibernate(struct device *dev)
> +{
> + return btintel_pcie_suspend_late(dev, PMSG_HIBERNATE);
> +}
> +
> +static int btintel_pcie_freeze(struct device *dev)
> +{
> + return btintel_pcie_suspend_late(dev, PMSG_FREEZE);
> +}
> +
> +static int btintel_pcie_resume(struct device *dev)
> +{
> + struct pci_dev *pdev = to_pci_dev(dev);
> + struct btintel_pcie_data *data;
> + ktime_t start;
> + int err;
> + s64 delta;
> +
> + data = pci_get_drvdata(pdev);
> + data->gp0_received = false;
> +
> + start = ktime_get();
> +
> + /* Refer: 6.4.11.7 -> Platform power management */
> + btintel_pcie_wr_sleep_cntrl(data, BTINTEL_PCIE_STATE_D0);
> + err = wait_event_timeout(data->gp0_wait_q, data->gp0_received,
> + msecs_to_jiffies(BTINTEL_DEFAULT_INTR_TIMEOUT_MS));
> + delta = ktime_to_ns(ktime_get() - start) / 1000;
> +
> + if (err == 0) {
> + bt_dev_err(data->hdev, "Timeout (%u ms) on alive interrupt for D0 entry",
> + BTINTEL_DEFAULT_INTR_TIMEOUT_MS);
> + return -EBUSY;
> + }
> + bt_dev_info(data->hdev, "device entered into d0 state from d3 in %lld us",
> + delta);
> + return 0;
> +}
> +
> +const struct dev_pm_ops btintel_pcie_pm_ops = {
> + .suspend = btintel_pcie_suspend,
> + .resume = btintel_pcie_resume,
> + .freeze = btintel_pcie_freeze,
> + .thaw = btintel_pcie_resume,
> + .poweroff = btintel_pcie_hibernate,
> + .restore = btintel_pcie_resume,
You should use pm_sleep_ptr() to avoid the ifdef clutter. It will ensure that
the compiler drops the function definitions when CONFIG_PM_SLEEP is not enabled.
> +};
> +#define BTINTELPCIE_PM_OPS (&btintel_pcie_pm_ops)
> +#else
> +#define BTINTELPCIE_PM_OPS NULL
> +#endif
> static struct pci_driver btintel_pcie_driver = {
> .name = KBUILD_MODNAME,
> .id_table = btintel_pcie_table,
> .probe = btintel_pcie_probe,
> .remove = btintel_pcie_remove,
> + .driver.pm = BTINTELPCIE_PM_OPS,
Here, you should use pm_ptr() for the same reason.
- Mani
--
மணிவண்ணன் சதாசிவம்
