Don't assume that only the driver would be accessing LNKCTL. ASPM policy changes can trigger write to LNKCTL outside of driver's control.

Use RMW capability accessors which does proper locking to avoid losing concurrent updates to the register value. On restore, clear the ASPMC field properly.

Fixes: 76d870ed09ab ("ath10k: enable ASPM") Suggested-by: Lukas Wunner lukas@wunner.de Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Acked-by: Kalle Valo kvalo@kernel.org Cc: stable@vger.kernel.org --- drivers/net/wireless/ath/ath10k/pci.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c index a7f44f6335fb..9275a672f90c 100644 --- a/drivers/net/wireless/ath/ath10k/pci.c +++ b/drivers/net/wireless/ath/ath10k/pci.c @@ -1963,8 +1963,9 @@ static int ath10k_pci_hif_start(struct ath10k *ar) ath10k_pci_irq_enable(ar); ath10k_pci_rx_post(ar);

- pcie_capability_write_word(ar_pci->pdev, PCI_EXP_LNKCTL, - ar_pci->link_ctl); + pcie_capability_clear_and_set_word(ar_pci->pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC, + ar_pci->link_ctl & PCI_EXP_LNKCTL_ASPMC);

return 0; } @@ -2821,8 +2822,8 @@ static int ath10k_pci_hif_power_up(struct ath10k *ar,

pcie_capability_read_word(ar_pci->pdev, PCI_EXP_LNKCTL, &ar_pci->link_ctl); - pcie_capability_write_word(ar_pci->pdev, PCI_EXP_LNKCTL, - ar_pci->link_ctl & ~PCI_EXP_LNKCTL_ASPMC); + pcie_capability_clear_word(ar_pci->pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC);

/* * Bring the target up cleanly.