[PATCH] Bluetooth: btintel_pcie: fix stale cache in set_dxstate fallback check
From: Vladimir V. Kondratyev
Date: Thu May 07 2026 - 16:36:05 EST
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: e57362f4911b ("Bluetooth: btintel_pcie: Add support for _suspend() / _resume()")
Signed-off-by: Vladimir V. Kondratyev <vladimirkondratyev2@xxxxxxxxx>
---
drivers/bluetooth/btintel_pcie.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index fda474406003..7fca8eea6e01 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -2778,9 +2778,13 @@ static int btintel_pcie_set_dxstate(struct btintel_pcie_data *data, u32 dxstate)
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.
+ * Refresh boot_stage_cache from hardware since it is only
+ * updated by the interrupt handler, then check if the
+ * controller reached the expected state and retry the
+ * operation only if it hasn't.
*/
+ 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;
--
2.54.0