Re: [PATCH] pci/hotplug: work-around for missing _RMV on HP ZBook G2
From: Jarod Wilson
Date: Mon May 18 2015 - 10:31:46 EST
On 5/16/2015 10:41 AM, Bjorn Helgaas wrote:
[fix Rafael's email address]
On Sat, May 16, 2015 at 09:37:50AM -0500, Bjorn Helgaas wrote:
Hi Jarod,
On Thu, May 14, 2015 at 03:33:58PM -0400, Jarod Wilson wrote:
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@xxxxxxxxxx>
CC: "Rafael J. Wysocki" <rjw@xxxxxxx>
CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: linux-acpi@xxxxxxxxxxxxxxx
CC: linux-pci@xxxxxxxxxxxxxxx
Signed-off-by: Jarod Wilson <jarod@xxxxxxxxxx>
---
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;
Oh, my goodness. I forgot how terrible this path is. Can anyone write a
simple explanation of how we choose to use acpiphp or pciehp? Module
parameters? A dummy driver that looks for duplicate slot numbers? Looking
for _ADR, _EJ0, _RMV? This is just nuts.
I can't really believe that we're doing this correctly.
If I understand correctly, the ZBooks don't have _RMV, but we try to use
acpiphp anyway, and acpiphp doesn't work?
They do have an _RMV entry for another device, whatever is on
0000:00:1c.0, which appears to be the thunderbolt port, but I have yet
to verify that (no thunderbolt devices to play with yet). The
expresscard slot is 0000:3c:02.0.
That sounds more like a problem
with our acpiphp/pciehp selection "algorithm" than a BIOS bug.
Jarod, can you open a report at http://bugzilla.kernel.org and attach a
complete dmesg log, "lspci -vv" output, and an acpidump? I'm particularly
interested in whether the BIOS granted us control over PCIe native hotplug.
If it did, I wonder why we would even attempt to use acpiphp.
Done:
https://bugzilla.kernel.org/show_bug.cgi?id=98581
--
Jarod Wilson
jarod@xxxxxxxxxx
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