Commit a3b0f10d authored by Naveen Naidu's avatar Naveen Naidu Committed by Bjorn Helgaas
Browse files

PCI: pciehp: Use PCI_POSSIBLE_ERROR() to check config reads 

When config pci_ops.read() can detect failed PCI transactions, the data
returned to the CPU is PCI_ERROR_RESPONSE (~0 or 0xffffffff).

Obviously a successful PCI config read may *also* return that data if a
config register happens to contain ~0, so it doesn't definitively indicate
an error unless we know the register cannot contain ~0.

Use PCI_POSSIBLE_ERROR() to check the response we get when we read data
from hardware.  This unifies PCI error response checking and makes error
checks consistent and easier to find.

Compile tested only.

Link: https://lore.kernel.org/r/e185b052fbfd530df703a36dd31126cb870eed95.1637243717.git.naveennaidu479@gmail.com


Signed-off-by: default avatarNaveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarLukas Wunner <lukas@wunner.de>
parent 242f288e

drivers/pci/hotplug/pciehp_hpc.c

+5 −5
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ static int pcie_poll_cmd(struct controller *ctrl, int timeout) 


	do {

		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);

		if (slot_status == (u16) ~0) {

		if (PCI_POSSIBLE_ERROR(slot_status)) {

			ctrl_info(ctrl, "%s: no response from device\n",

				  __func__);

			return 0;
@@ -165,7 +165,7 @@ 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) {

	if (PCI_POSSIBLE_ERROR(slot_ctrl)) {

		ctrl_info(ctrl, "%s: no response from device\n", __func__);

		goto out;

	}
@@ -236,7 +236,7 @@ int pciehp_check_link_active(struct controller *ctrl) 
	int ret;



	ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);

	if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0)

	if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(lnk_status))

		return -ENODEV;



	ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
@@ -443,7 +443,7 @@ int pciehp_card_present(struct controller *ctrl) 
	int ret;



	ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);

	if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)~0)

	if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(slot_status))

		return -ENODEV;



	return !!(slot_status & PCI_EXP_SLTSTA_PDS);
@@ -621,7 +621,7 @@ 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) {

	if (PCI_POSSIBLE_ERROR(status)) {

		ctrl_info(ctrl, "%s: no response from device\n", __func__);

		if (parent)

			pm_runtime_put(parent);