From: Bjorn Helgaas <helgaas@kernel.org>
To: Jesse Hathaway <jesse@mbuki-mvuki.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: Regression causes a hang on boot with a Comtrol PCI card
Date: Wed, 13 Mar 2019 18:21:13 -0500 [thread overview]
Message-ID: <20190313232112.GC210027@google.com> (raw)
In-Reply-To: <CANSNSoWiKd98Dt1N2sSjP9Af8zk1NPV-=3P4VLtFs_cSQG4RUg@mail.gmail.com>
Hi Jesse,
On Wed, Mar 13, 2019 at 11:50:07AM -0500, Jesse Hathaway wrote:
> Two regressions cause Linux to hang on boot when a Comtrol PCI card
> is present.
>
> If I revert the following two commits, I can boot again and the card
> operates without issue:
>
> 1302fcf0d03e (refs/bisect/bad) PCI: Configure *all* devices, not just
> hot-added ones
> 1c3c5eab1715 sched/core: Enable might_sleep() and smp_processor_id()
> checks early
I'm very sorry about the regression, but thank you very much for
narrowing it down and reporting it!
How did you narrow it down to *two* commits, and do you have to revert
both of them to avoid the hang? Usually a bisection identifies a
single commit, and the two you mention aren't related.
> ; lspci -vs 82:00.0
> 82:00.0 Multiport serial controller: Comtrol Corporation Device 0061
> Subsystem: Comtrol Corporation Device 0061
> Flags: 66MHz, medium devsel, IRQ 35, NUMA node 1
> Memory at c8004000 (32-bit, non-prefetchable) [size=4K]
> Memory at c8000000 (32-bit, non-prefetchable) [size=16K]
> Capabilities: [40] Hot-plug capable
> Capabilities: [48] Power Management version 2
> Kernel driver in use: rp2
> Kernel modules: rp2
>
> Is it possible that the problem is that the card claims to support
> Hot-plug, but does not?
>
> I would love to help fix this issue, please let me know what other
> information would be helpful to provide.
Can you collect a complete dmesg log (with a working kernel) and
output of "sudo lspci -vvxxx"? You can open a bug report at
https://bugzilla.kernel.org, attach the logs there, and respond here
with the URL.
Where does the hang happen? Is it when we configure the Comtrol card?
Bjorn
next prev parent reply other threads:[~2019-03-13 23:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-13 16:50 Regression causes a hang on boot with a Comtrol PCI card Jesse Hathaway
2019-03-13 23:21 ` Bjorn Helgaas [this message]
2019-03-14 20:57 ` Jesse Hathaway
2019-03-21 23:23 ` Bjorn Helgaas
2019-03-22 20:02 ` Jesse Hathaway
2019-04-01 19:43 ` Jesse Hathaway
2019-04-01 21:13 ` Bjorn Helgaas
2019-04-02 14:29 ` Alan Stern
2019-04-02 14:49 ` Mathias Nyman
2019-04-02 18:26 ` Alan Stern
2019-04-04 15:41 ` Jesse Hathaway
2019-04-04 17:16 ` Alan Stern
2019-04-04 17:36 ` Jesse Hathaway
2019-04-04 19:14 ` Alan Stern
2019-04-05 21:27 ` Jesse Hathaway
2019-04-06 15:32 ` Alan Stern
2019-04-15 21:47 ` Jesse Hathaway
2019-04-16 15:00 ` Alan Stern
2019-04-23 20:18 ` Jesse Hathaway
2019-04-24 14:20 ` Alan Stern
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