[PATCH v4 03/12] ath9k: Check if pcie_capability_read_*() reads ~0
From: Saheed O. Bolarinwa <hidden>
Date: 2020-07-31 12:02:27
Also in:
linux-kernel-mentees, linux-pci, linux-wireless, lkml
Subsystem:
atheros ath generic utilities, qualcomm atheros ath9k wireless driver, the rest · Maintainers:
Jeff Johnson, Toke Høiland-Jørgensen, Linus Torvalds
On failure pcie_capability_read_dword() sets it's last parameter, val to 0. However, with Patch 12/12, it is possible that val is set to ~0 on failure. This would introduce a bug because (x & x) == (~0 & x). Since ~0 is an invalid value here, Add an extra check for ~0 to the if condition to ensure success. Suggested-by: Bjorn Helgaas <redacted> Signed-off-by: Saheed O. Bolarinwa <redacted> --- drivers/net/wireless/ath/ath9k/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c
index f3461b193c7a..f02b243befef 100644
--- a/drivers/net/wireless/ath/ath9k/pci.c
+++ b/drivers/net/wireless/ath/ath9k/pci.c@@ -867,7 +867,8 @@ static void ath_pci_aspm_init(struct ath_common *common) 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)) { + if ((aspm != (u16)~0) && + (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);
--
2.18.4