Linux Hibernation with sata driver

[AYAN KUMAR HALDER]

Hi Varka,

This is a arm based custom platform in which we have both AMBA bus as
well as pci bus (pci slots which can fit addon cards).
There is no restriction(as far as I understand) that ARM based
platforms cannot have PCI bus.

Regards,
Ayan Kumar Halder


On Mon, Jun 2, 2014 at 1:28 PM, Varka Bhadram <varkab at cdac.in> wrote:
> My first doubt is why ARM is having PCI bus... ? I think it has AMBA Bus ...
>
>
> On June 1, 2014 at 11:40 PM AYAN KUMAR HALDER <ayankumarh at gmail.com> wrote:
>> Hi,
>>
>> I am working with Linux hibernation framework on ARM based custom SOC
>> which has SATA controller on PCI bus.
>>
>> I see that when the system resumes from hibernation, the SATA
>> controller(drivers/ata/ahci.c) on PCI bus fails to come up. My
>> understanding is that the hibernation calls 'freeze' of all devices.
>> The SATA controller receives the power state event as PM_EVENT_FREEZE
>> ( ie pdev->dev.power.power_state.event = PM_EVENT_FREEZE). Thus when
>> system restores the hibernation image, ahci_pci_device_resume gets
>> called in which ahci_pci_reset_controller/ahci_pci_init_controller
>> does not get called. So SATA controller fails to come up.
>>
>> Please let me know if my understanding is correct or not. If so, then
>> in ahci_pci_device_resume() should we change the following
>> if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND)
>> to
>> if (pdev->dev.power.power_state.event == PM_EVENT_FREEZE)
>>
>> In hibernation , as we power down the system, so I understand that the
>> sata controller need to be reset and re-initialized for proper
>> functioning.
>>
>> Regards,
>> Ayan Kumar Halder
>>
> Regards,
> Varka Bhadram
>
>
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