Thread (1 message) 1 message, 1 author, 2023-05-17
STALE1152d

Revision v2 of 4 in this series.

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[PATCH v2 7/9] wifi: ath11k: Use RMW accessors for changing LNKCTL

From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: 2023-05-17 10:58:32
Also in: ath11k, linux-pci, linux-wireless, lkml, stable
Subsystem: atheros ath generic utilities, qualcomm atheros ath11k wireless driver, the rest · Maintainers: Jeff Johnson, Linus Torvalds

Possibly related (same subject, not in this thread)

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(-)
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)
-- 
2.30.2
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