[3/4] acpi: pcihp: disable power control on PCIe slot

Commit Message

Igor Mammedov Feb. 24, 2022, 5:44 p.m. UTC

Previous patch [1] fixed unconditional power handling on a PCIe
slot, and make it honor PCI_EXP_SLTCAP_PCP capability.

Use COMPAT_PROP_PCP to disable power control (PCI_EXP_SLTCAP_PCP)
on PCIe slot when its plug callbacks are wired to ACPI pcihp,
which effectively leaves stop always powered.

PS:
See [1] for detailed description of the issue [2] and how it's
being addressed.

1) "pcie: update slot power status only is power control is enabled"

2)
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2053584
Signed-off-by: Igor Mammedov <[e-mail]>
---
 hw/acpi/pcihp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Patch

diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 6befd23e16..bc47d1bf64 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -32,6 +32,7 @@ 
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_host.h"
 #include "hw/pci/pcie_port.h"
+#include "hw/pci-bridge/xio3130_downstream.h"
 #include "hw/i386/acpi-build.h"
 #include "hw/acpi/acpi.h"
 #include "hw/pci/pci_bus.h"
@@ -329,6 +330,15 @@  void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
                                  GINT_TO_POINTER(pdev->acpi_index),
                                  g_cmp_uint32, NULL);
     }
+
+    /*
+     * since acpi_pcihp manages hotplug, disable PCI-E power control on slot
+     */
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PCIE_ROOT_PORT) ||
+        object_dynamic_cast(OBJECT(dev), TYPE_XIO3130_DOWNSTREAM)) {
+        object_property_set_bool(OBJECT(dev), COMPAT_PROP_PCP, false,
+                                 &error_abort);
+    }
 }
 
 void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,