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From:   Igor Mammedov <imammedo@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     Dongli Zhang <dongli.zhang@oracle.com>, linux-acpi@vger.kernel.org,
        linux-pci@vger.kernel.org, imammedo@redhat.com, mst@redhat.com,
        rafael@kernel.org, lenb@kernel.org, bhelgaas@google.com,
        mika.westerberg@linux.intel.com, boris.ostrovsky@oracle.com,
        joe.jin@oracle.com, stable@vger.kernel.org,
        Fiona Ebner <f.ebner@proxmox.com>,
        Thomas Lamprecht <t.lamprecht@proxmox.com>
Subject: [RFC 0/2] PCI: acpiphp: workaround race between hotplug and SCSI_SCAN_ASYNC job
Date:   Wed, 13 Dec 2023 01:36:12 +0100
Message-Id: <20231213003614.1648343-1-imammedo@redhat.com>
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Precedence: bulk

Hacks to mask a race between HBA scan job and bridge re-configuration(s)
during hotplug. 

I don't like it a bit but it something that could be done quickly
and solves problems that were reported.

Other options to discuss/possibly more invasive:
 1: make sure pci_assign_unassigned_bridge_resources() doesn't reconfigure
    bridge if it's not necessary.
 2. make SCSI_SCAN_ASYNC job wait till hotplug is finished for all slots on
    the bridge or somehow restart the job if it fails
 3. any other ideas?


1st reported: https://lore.kernel.org/r/9eb669c0-d8f2-431d-a700-6da13053ae54@proxmox.com

CC: Dongli Zhang <dongli.zhang@oracle.com>
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CC: Fiona Ebner <f.ebner@proxmox.com>
CC: Thomas Lamprecht <t.lamprecht@proxmox.com>

Igor Mammedov (2):
  PCI: acpiphp: enable slot only if it hasn't been enabled already
  PCI: acpiphp: slowdown hotplug if hotplugging multiple devices at a
    time

 drivers/pci/hotplug/acpiphp_glue.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

-- 
2.39.3