From: Bolarinwa Olayemi Saheed refactormyself@gmail.com
[ Upstream commit 9018fd7f2a73e9b290f48a56b421558fa31e8b75 ]
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: Bjorn Helgaas bjorn@helgaas.com Signed-off-by: Bolarinwa Olayemi Saheed refactormyself@gmail.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20200713175529.29715-3-refactormyself@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/net/wireless/intel/iwlegacy/common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c index e16f2597c2199..c1c1cf330de7f 100644 --- a/drivers/net/wireless/intel/iwlegacy/common.c +++ b/drivers/net/wireless/intel/iwlegacy/common.c @@ -4302,8 +4302,8 @@ il_apm_init(struct il_priv *il) * power savings, even without L1. */ if (il->cfg->set_l0s) { - pcie_capability_read_word(il->pci_dev, PCI_EXP_LNKCTL, &lctl); - if (lctl & PCI_EXP_LNKCTL_ASPM_L1) { + ret = pcie_capability_read_word(il->pci_dev, PCI_EXP_LNKCTL, &lctl); + if (!ret && (lctl & PCI_EXP_LNKCTL_ASPM_L1)) { /* L1-ASPM enabled; disable(!) L0S */ il_set_bit(il, CSR_GIO_REG, CSR_GIO_REG_VAL_L0S_ENABLED);