linux-kernel - Re: 3.8.0-rc4+ - Oops on removing WinTV-HVR-1400 expresscard TV Tuner

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Message-ID: <5148886F.8000809@googlemail.com>
Date:	Tue, 19 Mar 2013 15:46:55 +0000
From:	Chris Clayton <chris2553@...glemail.com>
To:	Bjorn Helgaas <bhelgaas@...gle.com>
CC:	Martin Mokrejs <mmokrejs@...d.natur.cuni.cz>,
	Yijing Wang <wangyijing@...wei.com>,
	Yijing Wang <wangyijing0307@...il.com>,
	LKML <linux-kernel@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>
Subject: Re: 3.8.0-rc4+ - Oops on removing WinTV-HVR-1400 expresscard TV Tuner

Hi Bjorn,

Sorry I meant to reply to your mail so that copy recipients will know 
the outcome of the things you asked me to do. But then I forgot. Doh! 
You should have received the attachment notification from bugzilla, I think.

On 03/15/13 22:48, Bjorn Helgaas wrote:
> On Tue, Mar 12, 2013 at 4:20 PM, Bjorn Helgaas <bhelgaas@...gle.com> wrote:
>> On Sat, Mar 9, 2013 at 2:20 AM, Chris Clayton <chris2553@...glemail.com> wrote:
>>> On 03/08/13 22:57, Bjorn Helgaas wrote:
>
>>>> Thanks.  I opened this bug report:
>>>> https://bugzilla.kernel.org/show_bug.cgi?id=54981 to keep track of
>>>> your logs.
>
> Hi Chris,
>
> The current Linux acpiphp driver doesn't do anything unless it finds
> devices with _EJ0 or _RMV methods, and your DSDT has neither.  But I
> think that implementation is incorrect because I'm not convinced that
> those methods are required in order to do hotplug via ACPI.  For
> example, your DSDT *does* have an _L01 method that does notifications
> to the root ports.  I suspect that hotplug events on your box generate
> an SCI that invokes that method.  Linux basically ignores the
> resulting notify events, and I suspect that hotplug works on Windows
> because it is paying attention to them.
>
> Can you build a kernel with CONFIG_ACPI_DEBUG=y, do the following, and
> attach all the output to the bugzilla?
>
> 1) Boot with empty ExpressCard slot (without using "pcie_ports=native")
> 2) # echo 0x00010004 > /sys/module/acpi/parameters/debug_layer
> 3) # echo 0x08000004 > /sys/module/acpi/parameters/debug_level
> 4) # lspci -vv
> 5) # setpci -s 1c.3 0x42.w
> 6) # setpci -s 1c.3 0x5a.w
> 7) # setpci -s 1c.3 0xd8.l
> 8) Insert ExpressCard
> 9) # setpci -s 1c.3 0x5a.w
> 10) # dmesg
>
> Here's what I think we'll see:
>
> - Slot Implemented (bit 8 of XCAP at 0x42) set, indicating a slot is
> implemented below this root port
> - Hot Plug SCI Enable (bit 30 of MPC at 0xd8) set, indicating that the
> root port should generate an SCI whenever a hotplug event is detected
> - Presence Detect State (bit 6 of SLTSTS at 0x5a) change from 0 with
> the slot empty to 1 with the slot occupied
> - pciehp doing nothing (since _OSC didn't grant the OS permission to
> use PCIe native hotplug)
> - dmesg indication of the SCI, leading to a Bus Check notification to
> \_SB.PCI0.RP04, which is the 1c.3 root port leading to the ExpressCard
> slot
>

As far as I can see, your predicted outcomes where correct. I've added 
the logs to the bugzilla report.

> A Bus Check notification means we're supposed to re-enumerate starting
> at that device.  If we *did* re-enumerate, we would find the new
> ExpressCard.
>
> Thanks,
>    Bjorn
>

Thanks,
Chris
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