[PATCH v3 3/3] PCI: pciehp: Add dmi table for in-band presence disabled

Stuart Hayes
2019-10-17T19:33:18Z

Some systems have in-band presence detection disabled for hot-plug PCI
slots, but do not report this in the slot capabilities 2 (SLTCAP2) register.
On these systems, presence detect can become active well after the link is
reported to be active, which can cause the slots to be disabled after a
device is connected.

Add a dmi table to flag these systems as having in-band presence disabled.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
---
drivers/pci/hotplug/pciehp_hpc.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 02eb811a014f..4d377a2a62ce 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -14,6 +14,7 @@

#define dev_fmt(fmt) "pciehp: " fmt

+#include <linux/dmi.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/jiffies.h>
@@ -26,6 +27,16 @@
#include "../pci.h"
#include "pciehp.h"

+static const struct dmi_system_id inband_presence_disabled_dmi_table[] = {
+ {
+ .ident = "Dell System",
+ .matches = {
+ DMI_MATCH(DMI_OEM_STRING, "Dell System"),
+ },
+ },
+ {}
+};
+
static inline struct pci_dev *ctrl_dev(struct controller *ctrl)
{
return ctrl->pcie->port;
@@ -895,6 +906,9 @@ struct controller *pcie_init(struct pcie_device *dev)
ctrl->inband_presence_disabled = 1;
}

+ if (dmi_first_match(inband_presence_disabled_dmi_table))
+ ctrl->inband_presence_disabled = 1;
+
/*
* If empty slot's power status is on, turn power off. The IRQ isn't
* requested yet, so avoid triggering a notification with this command.
--
2.18.1