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Bluetooth: btintel_pcie: fix stale cache in set_dxstate fallback check

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btintel_pcie returns -16 (EBUSY) during suspend, causing the entire
suspend operation to abort on Intel Lunar Lake hardware. The system
immediately resumes after every suspend attempt:

  Bluetooth: hci0: Timeout (200 ms) on alive interrupt for D2 entry, retry count 0
  Bluetooth: hci0: Timeout (200 ms) on alive interrupt for D2 entry, retry count 1
  Bluetooth: hci0: Timeout (200 ms) on alive interrupt for D2 entry, retry count 2
  btintel_pcie 0000:00:14.7: PM: pci_pm_suspend(): btintel_pcie_suspend [btintel_pcie] returns -16
  btintel_pcie 0000:00:14.7: PM: dpm_run_callback(): pci_pm_suspend returns -16
  btintel_pcie 0000:00:14.7: PM: failed to suspend async: error -16
  PM: Some devices failed to suspend, or early wake event detected

btintel_pcie_set_dxstate() falls back to checking the controller state via
btintel_pcie_in_d3/d0() when the alive interrupt is missed. However, these
helpers read boot_stage_cache, which is only updated by the interrupt
handler. As such, if the interrupt was missed, the cache is stale and the
fallback check always fails, exhausting all retries and returning -EBUSY,
causing suspend to abort.

The fix involves re-reading the hardware register before the fallback state
check, consistent with btintel_pcie_resume().

Fixes: 88c6216a52 ("Bluetooth: btintel_pcie: Suspend/Resume: Controller doorbell interrupt handling")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221481
Link: https://lore.kernel.org/linux-bluetooth/20260830151550.44687-1-lsa.uz@pm.me/
Signed-off-by: Vladimir V. Kondratyev <vladimirkondratyev2@gmail.com>
Tested-by: Sergey Lebedev <lsa.uz@pm.me>
Signed-off-by: Sergey Lebedev <lsa.uz@pm.me>
Signed-off-by: Ravindra <ravindra@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This commit is contained in:
Vladimir V. Kondratyev 2026-09-28 22:40:00 +05:30 committed by Luiz Augusto von Dentz
parent 7de1fcfb78
commit 12997a385f
2 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/bluetooth/btintel_pcie.c
View File

@ -4234,10 +4234,12 @@ static int btintel_pcie_set_dxstate(struct btintel_pcie_data *data, u32 dxstate)
BTINTEL_PCIE_CSR_MSIX_HW_INT_CAUSES,
BTINTEL_PCIE_MSIX_HW_INT_CAUSES_GP0);
/* A hardware bug may cause the alive interrupt to be missed.
* Check if the controller reached the expected state and retry
* the operation only if it hasn't.
/* A hardware bug may cause the alive interrupt to be missed. Refresh
* boot_stage_cache from hardware, since only the interrupt handler
* updates it. Finally retry only if the state check still fails.
*/
data->boot_stage_cache = btintel_pcie_rd_reg32(data,
BTINTEL_PCIE_CSR_BOOT_STAGE_REG);
if (dxstate == BTINTEL_PCIE_STATE_D0) {
if (btintel_pcie_in_d0(data))
return 0;

1
drivers/bluetooth/btintel_pcie.h
View File

@ -51,6 +51,7 @@
#define BTINTEL_PCIE_CSR_BOOT_STAGE_DEVICE_HALTED (BIT(14))
#define BTINTEL_PCIE_CSR_BOOT_STAGE_MAC_ACCESS_ON (BIT(16))
#define BTINTEL_PCIE_CSR_BOOT_STAGE_ALIVE (BIT(23))
/* Reflects live D-state. Updated by hardware on every D-state transition. */
#define BTINTEL_PCIE_CSR_BOOT_STAGE_D3_STATE_READY (BIT(24))
#define BTINTEL_PCIE_CSR_DOORBELL_MBOX_READ_CONFIRM (BIT(4))