This is a note to let you know that I've just added the patch titled wifi: ath12k: Use RMW accessors for changing LNKCTL to the 6.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-ath12k-use-rmw-accessors-for-changing-lnkctl.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 71cc3657aacf9b46c8171336ff4130cb53c1426e Author: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Date: Mon Jul 17 15:05:01 2023 +0300 wifi: ath12k: Use RMW accessors for changing LNKCTL [ Upstream commit f5a7ac118faf6d4f794975947b3300717eae8fc5 ] 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 do proper locking to avoid losing concurrent updates to the register value. On restore, clear the ASPMC field properly. Suggested-by: Lukas Wunner <lukas@xxxxxxxxx> Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Link: https://lore.kernel.org/r/20230717120503.15276-10-ilpo.jarvinen@xxxxxxxxxxxxxxx Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx> Acked-by: Kalle Valo <kvalo@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c index 9f174daf324c9..e1e45eb50f3e3 100644 --- a/drivers/net/wireless/ath/ath12k/pci.c +++ b/drivers/net/wireless/ath/ath12k/pci.c @@ -794,8 +794,8 @@ static void ath12k_pci_aspm_disable(struct ath12k_pci *ab_pci) u16_get_bits(ab_pci->link_ctl, PCI_EXP_LNKCTL_ASPM_L1)); /* disable L0s and L1 */ - pcie_capability_write_word(ab_pci->pdev, PCI_EXP_LNKCTL, - ab_pci->link_ctl & ~PCI_EXP_LNKCTL_ASPMC); + pcie_capability_clear_word(ab_pci->pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC); set_bit(ATH12K_PCI_ASPM_RESTORE, &ab_pci->flags); } @@ -803,8 +803,10 @@ static void ath12k_pci_aspm_disable(struct ath12k_pci *ab_pci) static void ath12k_pci_aspm_restore(struct ath12k_pci *ab_pci) { if (test_and_clear_bit(ATH12K_PCI_ASPM_RESTORE, &ab_pci->flags)) - pcie_capability_write_word(ab_pci->pdev, PCI_EXP_LNKCTL, - ab_pci->link_ctl); + pcie_capability_clear_and_set_word(ab_pci->pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC, + ab_pci->link_ctl & + PCI_EXP_LNKCTL_ASPMC); } static void ath12k_pci_kill_tasklets(struct ath12k_base *ab)