Commit f5a7ac11 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
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wifi: ath12k: Use RMW accessors for changing LNKCTL 



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: default avatarLukas Wunner <lukas@wunner.de>
Fixes: d8899132 ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Link: https://lore.kernel.org/r/20230717120503.15276-10-ilpo.jarvinen@linux.intel.com


Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Acked-by: default avatarKalle Valo <kvalo@kernel.org>
parent 6c1b6bdb

drivers/net/wireless/ath/ath12k/pci.c

+6 −4
Original line number Diff line number Diff line
@@ -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)