diff mbox series

[v3,09/10] wifi: ath12k: Use RMW accessors for changing LNKCTL

Message ID 20230620134624.99688-10-ilpo.jarvinen@linux.intel.com
State New
Headers
Series PCI: Improve PCIe Capability RMW concurrency control |

Commit Message

Ilpo Järvinen June 20, 2023, 1:46 p.m. UTC 
  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: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
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/ath12k/pci.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Comments

Simon Horman June 21, 2023, 2:47 p.m. UTC | #1 
On Tue, Jun 20, 2023 at 04:46:23PM +0300, Ilpo Järvinen wrote:
> 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: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
> 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/ath12k/pci.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)

Reviewed-by: Simon Horman <simon.horman@corigine.com>
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
index 9f174daf324c..e1e45eb50f3e 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)