Commit 9018fd7f authored by Bolarinwa Olayemi Saheed's avatar Bolarinwa Olayemi Saheed Committed by Kalle Valo

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: 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/20200713175529.29715-3-refactormyself@gmail.com
parent 0db5bc7b
......@@ -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);
......
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