Re: [PATCH] ahci: unregister acpi notify handler when a ZPODD is unbound

From: Aaron Lu
Date: Tue May 06 2014 - 03:32:41 EST


On 05/06/2014 03:14 PM, Levente Kurusa wrote:
> Hi,
>
> On 05/06/2014 08:07 AM, Aaron Lu wrote:
>> On 05/06/2014 02:02 PM, Levente Kurusa wrote:
>>> Hi,
>>>
>>> On 05/06/2014 05:16 AM, Aaron Lu wrote:
>>>> On 05/01/2014 12:04 AM, Levente Kurusa wrote:
>>>>> When a ZPODD device is unbound via sysfs, the acpi notify handler
>>>>> is not removed. This causes panics as observed in Bug #74601. The
>>>>
>>>> Ah...too bad, I forgot to consider this situation, thanks for tracking
>>>> this.
>>>>
>>>>> panic only happens when the wake happens from outside the kernel
>>>>> (i.e. inserting media or pressing a button). Implement a new
>>>>> ahci_remove_one function which causes zpodd_exit to be called for all
>>>>> ZPODD devices on the unbound PCI device.
>>>>>
>>>>> Signed-off-by: Levente Kurusa <levex@xxxxxxxxx>
>>>>> ---
>>>>>
>>>>> Hi,
>>>>>
>>>>> I am not sure if the loop below is correct. Maybe there is a better
>>>>> solution to loop through all the devices which might use ZPODD?
>>>>
>>>> I didn't find a proper place either. For hotplug, we did the zpodd_exit
>>>> at ata_scsi_handle_link_detach. But for host controller pci device
>>>> removal, we used scsi_remove_host in ata_port_detach and there is no
>>>> place to add the zpodd_exit for a to-be-removed scsi device...
>>>>
>>>> Looks like we can only iterate the ata devices and call zpodd_exit
>>>> explicitly for them if they are zpodd devices. Instead of adding a new
>>>> remove callback, what about just embed that into the ata_port_detach
>>>> like the following example?
>>>
>>> Yes, this makes more sense as this doesn't tinker with exports and such...
>>> However this will throw unused variable compiler warnings if we add the
>>> required #ifdefs... Maybe a new function? ata_zpodd_detach_port?
>>
>> I think we can omit the #ifdefs as the loop is not called frequently and
>> thus doesn't cost much. We already have stubs for zpodd_dev_enabled and
>> zpodd_exit.
>>
>
> Ah, I see. Shall I send V2? Any tags I should add for you?

Yes please. Also, this seems to be stable candidate.
You can add my reviewed-by tag, thanks.
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