svn commit: r351514 - head/sys/dev/pci

[Alexander Motin]

Author: mav
Date: Mon Aug 26 17:27:36 2019
New Revision: 351514
URL: https://svnweb.freebsd.org/changeset/base/351514

Log:
  Don't consider PCIe hot-plug command timeout fatal.
  
  According to my tests and errata to several generations of Intel CPUs,
  PCIe hot-plug command completion reporting is not very reliable thing.
  At least on my Supermicro X11DPi-NT board I never saw it reported.
  Before this change timeout code detached devices and tried to disable
  the slot, that in my case resulted in hot-plugged device being detached
  just a second after it was successfully detected and attached.  This
  change removes that, so in case of timeout it just prints the error and
  continue operation.  Linux does the same.
  
  MFC after:	1 week
  Sponsored by:	iXsystems, Inc.

Modified:
  head/sys/dev/pci/pci_pci.c

Modified: head/sys/dev/pci/pci_pci.c
==============================================================================
--- head/sys/dev/pci/pci_pci.c	Mon Aug 26 17:25:07 2019	(r351513)
+++ head/sys/dev/pci/pci_pci.c	Mon Aug 26 17:27:36 2019	(r351514)
@@ -1272,11 +1272,8 @@ pcib_pcie_cc_timeout(void *arg)
 	mtx_assert(&Giant, MA_OWNED);
 	sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
 	if (!(sta & PCIEM_SLOT_STA_CC)) {
-		device_printf(dev,
-		    "HotPlug Command Timed Out - forcing detach\n");
-		sc->flags &= ~(PCIB_HOTPLUG_CMD_PENDING | PCIB_DETACH_PENDING);
-		sc->flags |= PCIB_DETACHING;
-		pcib_pcie_hotplug_update(sc, 0, 0, true);
+		device_printf(dev, "HotPlug Command Timed Out\n");
+		sc->flags &= ~PCIB_HOTPLUG_CMD_PENDING;
 	} else {
 		device_printf(dev,
 	    "Missed HotPlug interrupt waiting for Command Completion\n");