[PATCH] pci/hotplug: work-around for missing _RMV on HP ZBook G2

Jarod Wilson
2015-05-14T19:34:23Z

The HP ZBook 15 and 17 Mobile Workstations, generation 2, up to and
including at least BIOS revision 01.07, do not have an ACPI _RMV object
associated with their expresscard slots, so acpi-based hotplug-capable
slot detection fails. If we fall back to pcie-based detection, the systems
work just fine, so this uses dmi matching to do that. With luck, a future
BIOS will remedy this (I've let someone at HP know about the problem),
but for now, just use this for all existing versions.

Note: they *do* have a proper _RMV object for what I believe is their
thunderbolt ports.

Tested successfully on an HP ZBook 17 G2 and HP ZBook 15 G2.

CC: Len Brown <lenb@kernel.org>
CC: "Rafael J. Wysocki" <rjw@sisk.pl>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: linux-acpi@vger.kernel.org
CC: linux-pci@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
---
drivers/pci/hotplug/pciehp_acpi.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
index 93cc926..db38fb5 100644
--- a/drivers/pci/hotplug/pciehp_acpi.c
+++ b/drivers/pci/hotplug/pciehp_acpi.c
@@ -28,6 +28,7 @@
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/dmi.h>
#include "pciehp.h"

#define PCIEHP_DETECT_PCIE (0)
@@ -109,10 +110,40 @@ static struct pcie_port_service_driver __initdata dummy_driver = {
.probe = dummy_probe,
};

+static int __init set_slot_detection_mode_pcie(const struct dmi_system_id *d)
+{
+ info("%s lacks ACPI _RMV object for expresscard\n", d->ident);
+ return 1;
+}
+
+static struct dmi_system_id __initdata missing_acpi_rmv[] = {
+ /* ZBook 17 through at least bios v01.07 */
+ {
+ .callback = set_slot_detection_mode_pcie,
+ .ident = "HP ZBook 17 G2 Mobile Workstation",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "HP ZBook 17 G2"),
+ },
+ },
+ /* ZBook 15 through at least bios v01.07 */
+ {
+ .callback = set_slot_detection_mode_pcie,
+ .ident = "HP ZBook 15 G2 Mobile Workstation",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "HP ZBook 15 G2"),
+ },
+ },
+ { .ident = NULL }
+};
+
static int __init select_detection_mode(void)
{
struct dummy_slot *slot, *tmp;

+ if (dmi_check_system(missing_acpi_rmv))
+ return PCIEHP_DETECT_PCIE;
if (pcie_port_service_register(&dummy_driver))
return PCIEHP_DETECT_ACPI;
pcie_port_service_unregister(&dummy_driver);
@@ -134,4 +165,6 @@ void __init pciehp_acpi_slot_detection_init(void)
out:
if (slot_detection_mode == PCIEHP_DETECT_ACPI)
info("Using ACPI for slot detection.\n");
+ else if (slot_detection_mode == PCIEHP_DETECT_PCIE)
+ info("Using PCIE-based slot detection.\n");
}
--
1.8.3.1