Re: [Update][PATCH 3/3] ACPI / dock / PCI: Synchronous handling ofdock events for PCI devices

From: Yinghai Lu
Date: Sun Jun 23 2013 - 19:12:46 EST


On Sun, Jun 23, 2013 at 2:42 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> On Sunday, June 23, 2013 01:29:19 PM Yinghai Lu wrote:
>> On Sun, Jun 23, 2013 at 12:57 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>> > On Sun, Jun 23, 2013 at 8:54 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote:
>> >> On 06/23/2013 05:25 AM, Rafael J. Wysocki wrote:
>> >>> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>> >>>
>> >>> The interactions between the ACPI dock driver and the ACPI-based PCI
>> >>> hotplug (acpiphp) are currently problematic because of ordering
>> >>> issues during hot-remove operations.
>> >>>
>> >>> First of all, the current ACPI glue code expects that physical
>> >>> devices will always be deleted before deleting the companion ACPI
>> >>> device objects. Otherwise, acpi_unbind_one() will fail with a
>> >>> warning message printed to the kernel log, for example:
>> >>>
>> >>> [ 185.026073] usb usb5: Oops, 'acpi_handle' corrupt
>> >>> [ 185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
>> >>> [ 185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
>> >>> [ 180.013656] port1: Oops, 'acpi_handle' corrupt
>> >>>
>> >> [...]
>> >>> @@ -597,15 +654,11 @@ register_hotplug_dock_device(acpi_handle
>> >>> * ops
>> >>> */
>> >>> dd = find_dock_dependent_device(dock_station, handle);
>> >>> - if (dd) {
>> >>> - dd->ops = ops;
>> >>> - dd->context = context;
>> >>> - dock_add_hotplug_device(dock_station, dd);
>> >>> - ret = 0;
>> >>> - }
>> >>> + if (dd)
>> >>> + return dock_init_hotplug(dd, ops, context,
>> >>> + init, release);
>> >> Hi Rafael,
>> >> Seems not an equivalent change. According to the comment just above the
>> >> code, we shouldn't return but continue here.
>> >> /*
>> >> * An ATA bay can be in a dock and itself can be ejected
>> >> * separately, so there are two 'dock stations' which need the
>> >> * ops
>> >> */
>> >
>> > two dock stations:
>> > Do you mean two dock station has same handle?
>> >
>> > dock_add should add correctly flags for IS_DOCK and IS_ATA.
>> > if one handle has _DCK and _GTF etc.
>> >
>> > or do you mean there are two dependent devices with same handle?
>> > like one is for acpiphp slot and one is for ATA?
>>
>> related commit:
>> commit 61b836958371c717d1e6d4fea1d2c512969ad20b
>> Author: Shaohua Li <shaohua.li@xxxxxxxxx>
>> Date: Thu Aug 28 10:07:14 2008 +0800
>>
>> dock: fix for ATA bay in a dock station
>>
>> an ATA bay can be in a dock and itself can be ejected separately.
>> This patch handles such eject bay. Found by Holger.
>>
>> Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
>> Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
>> @@ -618,16 +619,21 @@ register_hotplug_dock_device(acpi_handle handle, struct ac
>> pi_dock_ops *ops,
>> * this would include the dock station itself
>> */
>> list_for_each_entry(dock_station, &dock_stations, sibiling) {
>> + /*
>> + * An ATA bay can be in a dock and itself can be ejected
>> + * seperately, so there are two 'dock stations' which need the
>> + * ops
>> + */
>> dd = find_dock_dependent_device(dock_station, handle);
>> if (dd) {
>> dd->ops = ops;
>> dd->context = context;
>> dock_add_hotplug_device(dock_station, dd);
>> - return 0;
>> + ret = 0;
>> }
>> }
>>
>> - return -EINVAL;
>> + return ret;
>> }
>>
>> so two doc station with different handle.
>>
>> and dependent devices in both...
>>
>> looks like Rafael's change can not handle this case anymore.
>
> Ah, I overlooked the fact that each dock station is on its own dependent_list
> and can also be on another dock station's dependent_list. I'm not sure if that
> makes sense, but let's not break the backwards compatibility here.

wonder if dock_release_hotplug with second dock_station and dd will
have problem.

as first one dock_station/dd, could have hp_context release already,
then second one could all release(context) again....

so looks like dock_release_hotplug should go over dock_station/dd list
to clear hp_context in other dock_station/... if they are the same?

Yinghai
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