[PATCH 5/11 RFC] PCI: pciehp: Make "Power On" the default

From: Saheed Olayemi Bolarinwa
Date: Mon Jul 06 2020 - 06:32:01 EST


From: Bolarinwa Olayemi Saheed <refactormyself@xxxxxxxxx>

The default case of the switch statement is redundant since
PCI_EXP_SLTCTL_PCC is only a single bit. pcie_capability_read_word()
currently causes "On" value to be set if it fails. Patch 11/11
changes the behaviour of pcie_capability_read_word() so on falure the
"Off" value will be set.

Make the function set status to "Power On" by default and only set to
Set "Power Off" only if pcie_capability_read_word() is successful and
(slot_ctrl & PCI_EXP_SLTCTL_PCC) == PCI_EXP_SLTCTL_PWR_OFF.

Suggested-by: Bjorn Helgaas <bjorn@xxxxxxxxxxx>
Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@xxxxxxxxx>
---
drivers/pci/hotplug/pciehp_hpc.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 0b691e37fd04..78f806a9c6f1 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -399,22 +399,16 @@ void pciehp_get_power_status(struct controller *ctrl, u8 *status)
{
struct pci_dev *pdev = ctrl_dev(ctrl);
u16 slot_ctrl;
+ int ret;

- pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
+ *status = 1; /* On */
+ ret = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);

- switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
- case PCI_EXP_SLTCTL_PWR_ON:
- *status = 1; /* On */
- break;
- case PCI_EXP_SLTCTL_PWR_OFF:
+ if (!ret &&
+ ((slot_ctrl & PCI_EXP_SLTCTL_PCC) == PCI_EXP_SLTCTL_PWR_OFF))
*status = 0; /* Off */
- break;
- default:
- *status = 0xFF;
- break;
- }
}

void pciehp_get_latch_status(struct controller *ctrl, u8 *status)
--
2.18.2