git: 9be42ee6c9c7 - main - pci: Make PCIe Eject timeout configurable

From: Colin Percival <cperciva_at_FreeBSD.org>
Date: Wed, 02 Apr 2025 20:14:39 UTC
The branch main has been updated by cperciva:

URL: https://cgit.FreeBSD.org/src/commit/?id=9be42ee6c9c741052bdc49f13bc953bf88a24423

commit 9be42ee6c9c741052bdc49f13bc953bf88a24423
Author:     Colin Percival <cperciva@FreeBSD.org>
AuthorDate: 2025-03-31 04:08:44 +0000
Commit:     Colin Percival <cperciva@FreeBSD.org>
CommitDate: 2025-04-02 20:14:24 +0000

    pci: Make PCIe Eject timeout configurable
    
    PCIe mandates a 5 second delay between when the "Attention Button" is
    pressed and when the associated device is detached; this is to allow
    for the button to be pressed a second time to cancel the ejection.  On
    some systems this 5 second delay may not be desireable; so introduce a
    hw.pci.pcie_hp_detach_timeout sysctl (which can also be set as a loader
    tunable) which specifies the timeout in milliseconds (default 5000).
    If set to zero, the device is detached immediately.
    
    Reviewed by:    jhb
    MFC after:      2 weeks
    Sponsored by:   Amazon
    Differential Revision:  https://reviews.freebsd.org/D49585
---
 sys/dev/pci/pci_pci.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/sys/dev/pci/pci_pci.c b/sys/dev/pci/pci_pci.c
index 10133c0c68d9..5e71a376604b 100644
--- a/sys/dev/pci/pci_pci.c
+++ b/sys/dev/pci/pci_pci.c
@@ -800,6 +800,11 @@ SYSCTL_INT(_hw_pci, OID_AUTO, enable_pcie_hp, CTLFLAG_RDTUN,
     &pci_enable_pcie_hp, 0,
     "Enable support for native PCI-express HotPlug.");
 
+static sbintime_t pcie_hp_detach_timeout = 5 * SBT_1S;
+SYSCTL_SBINTIME_MSEC(_hw_pci, OID_AUTO, pcie_hp_detach_timeout, CTLFLAG_RWTUN,
+    &pcie_hp_detach_timeout,
+    "Attention Button delay for PCI-express Eject.");
+
 static void
 pcib_probe_hotplug(struct pcib_softc *sc)
 {
@@ -1068,11 +1073,17 @@ pcib_pcie_intr_hotplug(void *arg)
 			    &sc->pcie_ab_task, NULL);
 		} else if (old_slot_sta & PCIEM_SLOT_STA_PDS) {
 			/* Only initiate detach sequence if device present. */
-			device_printf(dev,
-		    "Attention Button Pressed: Detaching in 5 seconds\n");
-			sc->flags |= PCIB_DETACH_PENDING;
-			taskqueue_enqueue_timeout(taskqueue_bus,
-			    &sc->pcie_ab_task, 5 * hz);
+			if (pcie_hp_detach_timeout != 0) {
+				device_printf(dev,
+			    "Attention Button Pressed: Detaching in %ld ms\n",
+			    (long)(pcie_hp_detach_timeout / SBT_1MS));
+				sc->flags |= PCIB_DETACH_PENDING;
+				taskqueue_enqueue_timeout_sbt(taskqueue_bus,
+				    &sc->pcie_ab_task, pcie_hp_detach_timeout,
+				    SBT_1S, 0);
+			} else {
+				sc->flags |= PCIB_DETACHING;
+			}
 		}
 	}
 	if (sc->pcie_slot_sta & PCIEM_SLOT_STA_PFD)