| Message ID | 20230517105235.29176-8-ilpo.jarvinen@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: Improve PCIe Capability RMW concurrency control | expand |
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> writes: > 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. > > Fixes: e9603f4bdcc0 ("ath11k: pci: disable ASPM L0sLs before downloading firmware") > Suggested-by: Lukas Wunner <lukas@wunner.de> > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> > Cc: stable@vger.kernel.org Acked-by: Kalle Valo <kvalo@kernel.org>
diff --git a/drivers/net/wireless/ath/ath11k/pci.c b/drivers/net/wireless/ath/ath11k/pci.c index 7b33731a50ee..6ba4cef6b1c7 100644 --- a/drivers/net/wireless/ath/ath11k/pci.c +++ b/drivers/net/wireless/ath/ath11k/pci.c @@ -581,8 +581,8 @@ static void ath11k_pci_aspm_disable(struct ath11k_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(ATH11K_PCI_ASPM_RESTORE, &ab_pci->flags); } @@ -590,8 +590,10 @@ static void ath11k_pci_aspm_disable(struct ath11k_pci *ab_pci) static void ath11k_pci_aspm_restore(struct ath11k_pci *ab_pci) { if (test_and_clear_bit(ATH11K_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 int ath11k_pci_power_up(struct ath11k_base *ab)
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. Fixes: e9603f4bdcc0 ("ath11k: pci: disable ASPM L0sLs before downloading firmware") Suggested-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: stable@vger.kernel.org --- drivers/net/wireless/ath/ath11k/pci.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)