[PATCH 2/2] net: wwan: iosm: Keep device at D0 for s2idle case

From: Kai-Heng Feng
Date: Fri Dec 24 2021 - 03:20:28 EST


We are seeing spurious wakeup caused by Intel 7560 WWAN on AMD laptops.
This prevent those laptops to stay in s2idle state.

>From what I can understand, the intention of ipc_pcie_suspend() is to
put the device to D3cold, and ipc_pcie_suspend_s2idle() is to keep the
device at D0. However, the device can still be put to D3hot/D3cold by
PCI core.

So explicitly let PCI core know this device should stay at D0, to solve
the spurious wakeup.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
---
drivers/net/wwan/iosm/iosm_ipc_pcie.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
index d73894e2a84ed..af1d0e837fe99 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_pcie.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
@@ -340,6 +340,9 @@ static int __maybe_unused ipc_pcie_suspend_s2idle(struct iosm_pcie *ipc_pcie)

ipc_imem_pm_s2idle_sleep(ipc_pcie->imem, true);

+ /* Let PCI core know this device should stay at D0 */
+ pci_save_state(ipc_pcie->pci);
+
return 0;
}

--
2.33.1