From 9018fd7f2a73e9b290f48a56b421558fa31e8b75 Mon Sep 17 00:00:00 2001 From: Bolarinwa Olayemi Saheed Date: Mon, 13 Jul 2020 19:55:27 +0200 Subject: [Backport 9018fd7f2a73] iwlegacy: 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: Bjorn Helgaas Signed-off-by: Bolarinwa Olayemi Saheed Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20200713175529.29715-3-refactormyself@gmail.com --- src/common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/common.c b/src/common.c index 348c17ce72f5cd57b66fb5ae161b2381b3585bf3..f78e062df572abacb6ab7d3a271de85f5903247d 100644 --- a/src/common.c +++ b/src/common.c @@ -4286,8 +4286,8 @@ 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); -- 2.31.1