Don't assume that only the driver would be accessing LNKCTL. ASPM policy changes can trigger write to LNKCTL outside of driver's control. And in the case of upstream (parent), the driver does not even own the device it's changing LNKCTL for. Use pcie_lnkctl_clear_and_set() which does proper locking to avoid losing concurrent updates to the register value. Suggested-by: Lukas Wunner <lukas@xxxxxxxxx> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> --- drivers/net/wireless/mediatek/mt76/pci.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/pci.c b/drivers/net/wireless/mediatek/mt76/pci.c index 4c1c159fbb62..8c6444f5fac3 100644 --- a/drivers/net/wireless/mediatek/mt76/pci.c +++ b/drivers/net/wireless/mediatek/mt76/pci.c @@ -39,9 +39,8 @@ void mt76_pci_disable_aspm(struct pci_dev *pdev) /* 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); + pcie_lnkctl_clear_and_set(pdev, aspm_conf, 0); if (parent) - pcie_capability_clear_word(parent, PCI_EXP_LNKCTL, - aspm_conf); + pcie_lnkctl_clear_and_set(parent, aspm_conf, 0); } EXPORT_SYMBOL_GPL(mt76_pci_disable_aspm); -- 2.30.2
