netdev - [PATCH net-next] Revert "net: wwan: iosm: Keep device at D0 for s2idle case"

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Message-Id: <20220104150213.1894-1-m.chetan.kumar@linux.intel.com>
Date:   Tue,  4 Jan 2022 20:32:13 +0530
From:   M Chetan Kumar <m.chetan.kumar@...ux.intel.com>
To:     netdev@...r.kernel.org
Cc:     kuba@...nel.org, davem@...emloft.net, johannes@...solutions.net,
        ryazanov.s.a@...il.com, loic.poulain@...aro.org,
        krishna.c.sudi@...el.com, m.chetan.kumar@...el.com,
        m.chetan.kumar@...ux.intel.com, linuxwwan@...el.com,
        kai.heng.feng@...onical.com
Subject: [PATCH net-next] Revert "net: wwan: iosm: Keep device at D0 for s2idle case"

Depending on BIOS configuration IOSM driver exchanges
protocol required for putting device into D3L2 or D3L1.2.

ipc_pcie_suspend_s2idle() is implemented to put device to D3L1.2.

This patch forces PCI core know this device should stay at D0.
- pci_save_state()is expensive since it does a lot of slow PCI
config reads.

The reported issue is not observed on x86 platform. The supurios
wake on AMD platform needs to be futher debugged with orignal patch
submitter [1]. Also the impact of adding pci_save_state() needs to be
assessed by testing it on other platforms.

This reverts commit f4dd5174e273("net: wwan: iosm: Keep device
at D0 for s2idle case").

[1] https://lore.kernel.org/all/20211224081914.345292-2-kai.heng.feng@canonical.com/

Signed-off-by: M Chetan Kumar <m.chetan.kumar@...ux.intel.com>
---
 drivers/net/wwan/iosm/iosm_ipc_pcie.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/wwan/iosm/iosm_ipc_pcie.c b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
index af1d0e837fe9..d73894e2a84e 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_pcie.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_pcie.c
@@ -340,9 +340,6 @@ 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;
 }
 
-- 
2.25.1