[PATCH 3/14 v3] ath9k: Check the return value of pcie_capability_read_*()

[PATCH 3/14 v3] ath9k: Check the return value of pcie_capability_read_*()

[Saheed O. Bolarinwa]

From: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>

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>

---
 drivers/net/wireless/ath/ath9k/pci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c
index f3461b193c7a..cff9af3af38d 100644
--- a/drivers/net/wireless/ath/ath9k/pci.c
+++ b/drivers/net/wireless/ath/ath9k/pci.c
@@ -825,6 +825,7 @@ static void ath_pci_aspm_init(struct ath_common *common)
 	struct pci_dev *pdev = to_pci_dev(sc->dev);
 	struct pci_dev *parent;
 	u16 aspm;
+	int ret;
 
 	if (!ah->is_pciexpress)
 		return;
@@ -866,8 +867,8 @@ static void ath_pci_aspm_init(struct ath_common *common)
 	if (AR_SREV_9462(ah))
 		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)) {
+	ret = pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &aspm);
+	if (!ret && (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);
-- 
2.18.2

[PATCH 4/14 v3] iwlegacy: Check the return value of pcie_capability_read_*()

[Saheed O. Bolarinwa]

From: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>

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>

---
 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 348c17ce72f5..f78e062df572 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);
-- 
2.18.2

Re: [PATCH 4/14 v3] iwlegacy: Check the return value of pcie_capability_read_*()

[Kalle Valo]

"Saheed O. Bolarinwa" <refactormyself@gmail.com> wrote:

> From: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>
> 
> 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>

Patch applied to wireless-drivers-next.git, thanks.

9018fd7f2a73 iwlegacy: Check the return value of pcie_capability_read_*()

-- 
https://patchwork.kernel.org/patch/11660739/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH 3/14 v3] ath9k: Check the return value of pcie_capability_read_*()

[Kalle Valo]

"Saheed O. Bolarinwa" <refactormyself@gmail.com> wrote:

> 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>

Patch applied to ath-next branch of ath.git, thanks.

9a8ab2bfb678 ath9k: Check the return value of pcie_capability_read_*()

-- 
https://patchwork.kernel.org/patch/11660731/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches