From: Bolarinwa Olayemi Saheed <[email protected]> On any failure pcie_capability_read_word() sets it's last parameter, *val to 0, this value may have be earlier set by pci_config_read_word() to ~0. So, any function which check only for a frabricated ~0 will fail in this case.
Checking for the return value of pcie_capability_read_dword() will help assert failure or success of this function. But more checks may be needed to assure the validity of the value. Include a check on the return value of pcie_capability_read_word() to confirm success or failure. Suggested-by: Bjorn Helgaas <[email protected]> Signed-off-by: Bolarinwa Olayemi Saheed <[email protected]> --- drivers/pci/hotplug/pciehp_hpc.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 53433b37e181..5af281d97d4f 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -86,10 +86,11 @@ static int pcie_poll_cmd(struct controller *ctrl, int timeout) { struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_status; + int ret; do { - pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (slot_status == (u16) ~0) { + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (ret || (slot_status == (u16) ~0)) { ctrl_info(ctrl, "%s: no response from device\n", __func__); return 0; @@ -156,6 +157,7 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd, { struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_ctrl_orig, slot_ctrl; + int ret; mutex_lock(&ctrl->ctrl_lock); @@ -164,8 +166,8 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd, */ pcie_wait_cmd(ctrl); - pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); - if (slot_ctrl == (u16) ~0) { + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); + if (ret || (slot_ctrl == (u16) ~0)) { ctrl_info(ctrl, "%s: no response from device\n", __func__); goto out; } @@ -430,7 +432,7 @@ void pciehp_get_latch_status(struct controller *ctrl, u8 *status) * removed immediately after the check so the caller may need to take * this into account. * - * It the hotplug controller itself is not available anymore returns + * If the hotplug controller itself is not available anymore returns * %-ENODEV. */ int pciehp_card_present(struct controller *ctrl) @@ -591,8 +593,8 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) } read_status: - pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status); - if (status == (u16) ~0) { + ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status); + if (ret || (status == (u16) ~0)) { ctrl_info(ctrl, "%s: no response from device\n", __func__); if (parent) pm_runtime_put(parent); -- 2.18.2
