[PATCH v1 06/11] PCI/PM: Write 0 to PMCSR in pci_power_up() in all cases

Rafael J. Wysocki
2022-05-05T18:31:58Z

Make pci_power_up() write 0 to the device's PCI_PM_CTRL register in
order to put it into D0 regardless of the power state returned by
the previous read from that register which should not matter.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/pci/pci.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1230,15 +1230,10 @@ int pci_power_up(struct pci_dev *dev)
}

/*
- * If we're (effectively) in D3, force entire word to 0. This doesn't
- * affect PME_Status, disables PME_En, and sets PowerState to 0.
+ * Force the entire word to 0. This doesn't affect PME_Status, disables
+ * PME_En, and sets PowerState to 0.
*/
- if (state == PCI_D3hot)
- pmcsr = 0;
- else
- pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
-
- pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
+ pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0);

/* Mandatory transition delays; see PCI PM 1.2. */
if (state == PCI_D3hot)