From: Ross Lagerwall <ross.lagerwall@citrix.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: <linux-pci@vger.kernel.org>
Subject: Regression caused by "PCI: Probe for device reset support during enumeration"
Date: Fri, 14 Dec 2018 13:15:58 +0000 [thread overview]
Message-ID: <b859f604-17bc-243c-5d0f-65b02c5cd24d@citrix.com> (raw)
Hi Bjorn,
Your commit 5b0764cac9f1 ("PCI: Probe for device reset support during
enumeration") moved checking whether a device could be reset much
earlier to when the device is first probed. When the device is first
probed, the other devices on the bus may not have been discovered yet.
This means that we will claim to support SBR as a reset mechanism
because it is the only device behind the bus at that pointer meanwhile
the others simply haven't been discovered yet. This results in
dev->reset_fn being incorrectly set to true and a reset file being
created. When userspace actually tries to use the reset file it fails
because now there are other sibling devices preventing the use of an SBR.
How can this best be fixed? I was considering moving the check to the
end of pci_bus_add_devices(), but I'm not at all familiar with the code
so perhaps there is a better way.
Thanks,
--
Ross Lagerwall
next reply other threads:[~2018-12-14 13:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-14 13:15 Ross Lagerwall [this message]
2018-12-14 17:18 ` Regression caused by "PCI: Probe for device reset support during enumeration" Bjorn Helgaas
2018-12-14 18:40 ` Alex Williamson
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