| From 49f2ae4ef9727db61d104d89bf73e184abf56b2f Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 13 Jul 2020 19:55:27 +0200 |
| Subject: iwlegacy: Check the return value of pcie_capability_read_*() |
| |
| 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> |
| --- |
| 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 348c17ce72f5c..f78e062df572a 100644 |
| --- a/drivers/net/wireless/intel/iwlegacy/common.c |
| +++ b/drivers/net/wireless/intel/iwlegacy/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); |
| -- |
| 2.25.1 |
| |
