Commit 9a8ab2bf authored by Bolarinwa Olayemi Saheed's avatar Bolarinwa Olayemi Saheed Committed by Kalle Valo
Browse files

ath9k: Check the return value of pcie_capability_read_*() 



On failure pcie_capability_read_dword() sets it's last parameter, val
to 0. However, with Patch 14/14, it is possible that val is set to ~0 on
failure. This would introduce a bug because (x & x) == (~0 & x).

This bug can be avoided without changing the function's behaviour if the
return value of pcie_capability_read_dword is checked to confirm success.

Check the return value of pcie_capability_read_dword() to ensure success.

Suggested-by: default avatarBjorn Helgaas <bjorn@helgaas.com>
Signed-off-by: default avatarBolarinwa Olayemi Saheed <refactormyself@gmail.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200713175529.29715-2-refactormyself@gmail.com
parent a9bf0909

drivers/net/wireless/ath/ath9k/pci.c

+3 −2
Original line number Diff line number Diff line
@@ -825,6 +825,7 @@ static void ath_pci_aspm_init(struct ath_common *common) 
	struct pci_dev *pdev = to_pci_dev(sc->dev);

	struct pci_dev *parent;

	u16 aspm;

	int ret;



	if (!ah->is_pciexpress)

		return;
@@ -866,8 +867,8 @@ static void ath_pci_aspm_init(struct ath_common *common) 
	if (AR_SREV_9462(ah))

		pci_read_config_dword(pdev, 0x70c, &ah->config.aspm_l1_fix);



	pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &aspm);

	if (aspm & (PCI_EXP_LNKCTL_ASPM_L0S | PCI_EXP_LNKCTL_ASPM_L1)) {

	ret = pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &aspm);

	if (!ret && (aspm & (PCI_EXP_LNKCTL_ASPM_L0S | PCI_EXP_LNKCTL_ASPM_L1))) {

		ah->aspm_enabled = true;

		/* Initialize PCIe PM and SERDES registers. */

		ath9k_hw_configpcipowersave(ah, false);