48 lines
1.2 KiB
C
48 lines
1.2 KiB
C
|
// SPDX-License-Identifier: ISC
|
||
|
|
/*
|
||
|
|
* Copyright (C) 2019 Lorenzo Bianconi <lorenzo@kernel.org>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "mt76.h"
|
||
|
|
#include <linux/pci.h>
|
||
|
|
|
||
|
|
void mt76_pci_disable_aspm(struct pci_dev *pdev)
|
||
|
|
{
|
||
|
|
struct pci_dev *parent = pdev->bus->self;
|
||
|
|
u16 aspm_conf, parent_aspm_conf = 0;
|
||
|
|
|
||
|
|
pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &aspm_conf);
|
||
|
|
aspm_conf &= PCI_EXP_LNKCTL_ASPMC;
|
||
|
|
if (parent) {
|
||
|
|
pcie_capability_read_word(parent, PCI_EXP_LNKCTL,
|
||
|
|
&parent_aspm_conf);
|
||
|
|
parent_aspm_conf &= PCI_EXP_LNKCTL_ASPMC;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!aspm_conf && (!parent || !parent_aspm_conf)) {
|
||
|
|
/* aspm already disabled */
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
dev_info(&pdev->dev, "disabling ASPM %s %s\n",
|
||
|
|
(aspm_conf & PCI_EXP_LNKCTL_ASPM_L0S) ? "L0s" : "",
|
||
|
|
(aspm_conf & PCI_EXP_LNKCTL_ASPM_L1) ? "L1" : "");
|
||
|
|
|
||
|
|
if (IS_ENABLED(CONFIG_PCIEASPM)) {
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = pci_disable_link_state(pdev, aspm_conf);
|
||
|
|
if (!err)
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* both device and parent should have the same ASPM setting.
|
||
|
|
* disable ASPM in downstream component first and then upstream.
|
||
|
|
*/
|
||
|
|
pcie_capability_clear_word(pdev, PCI_EXP_LNKCTL, aspm_conf);
|
||
|
|
if (parent)
|
||
|
|
pcie_capability_clear_word(parent, PCI_EXP_LNKCTL,
|
||
|
|
aspm_conf);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(mt76_pci_disable_aspm);
|