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authorStuart Hayes <stuart.w.hayes@gmail.com>2019-10-25 21:00:47 +0200
committerBjorn Helgaas <bhelgaas@google.com>2020-02-21 05:48:45 +0100
commit0b382546d863f2f09eecaccda95a0b4bfd148f92 (patch)
treee64da0557b2ceee434f3a6f64efe522853886ce9 /drivers/pci/hotplug
parentPCI: pciehp: Wait for PDS if in-band presence is disabled (diff)
downloadlinux-0b382546d863f2f09eecaccda95a0b4bfd148f92.tar.xz
linux-0b382546d863f2f09eecaccda95a0b4bfd148f92.zip
PCI: pciehp: Add DMI table for in-band presence detection disabled
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 detect disabled. Link: https://lore.kernel.org/r/20191025190047.38130-4-stuart.w.hayes@gmail.com Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Lukas Wunner <lukas@wunner.de>
Diffstat (limited to 'drivers/pci/hotplug')
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index bb9ad0032e6b..e4627c68b30f 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 +27,24 @@
#include "../pci.h"
#include "pciehp.h"
+static const struct dmi_system_id inband_presence_disabled_dmi_table[] = {
+ /*
+ * Match all Dell systems, as some Dell systems have inband
+ * presence disabled on NVMe slots (but don't support the bit to
+ * report it). Setting inband presence disabled should have no
+ * negative effect, except on broken hotplug slots that never
+ * assert presence detect--and those will still work, they will
+ * just have a bit of extra delay before being probed.
+ */
+ {
+ .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;
@@ -909,6 +928,9 @@ 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;
+
/* Check if Data Link Layer Link Active Reporting is implemented */
pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);