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Subject: Re: [PATCH v3 0/3] drivers: ide: use generic power management
To:     Vaibhav Gupta <vaibhav.varodek@gmail.com>
Cc:     Vaibhav Gupta <vaibhavgupta40@gmail.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>, bjorn@helgaas.com,
        "David S. Miller" <davem@davemloft.net>,
        linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        skhan@linuxfoundation.org, linux-ide@vger.kernel.org
From:   Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Message-ID: <834eb293-bd4f-626c-4558-fbf71a5999f0@samsung.com>
Date:   Tue, 14 Jul 2020 10:19:06 +0200
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On 7/14/20 9:52 AM, Vaibhav Gupta wrote:
> On Tue, Jul 14, 2020 at 09:32:56AM +0200, Bartlomiej Zolnierkiewicz wrote:
>>
>> Hi,
>>
>> On 7/13/20 7:36 PM, Vaibhav Gupta wrote:
>>> Linux Kernel Mentee: Remove Legacy Power Management.
>>>
>>> The purpose of this patch series is to remove legacy power management callbacks
>>> from ide drivers.
>>>
>>> The suspend() and resume() callbacks operations are still invoking
>>> pci_save/restore_state(), pci_set_power_state(), pci_enable/disable_state(),
>>> etc. and handling the power management themselves, which is not recommended.
>>>
>>> The conversion requires the removal of the those function calls and change the
>>> callback definition accordingly and make use of dev_pm_ops structure.
>>
>> IDE subsystem (drivers/ide/) is deprecated and has been superseded by libata
>> subsystem (drivers/ata/).
>>
>> libata drivers have the same issue so please concentrate on fixing them
>> first. Later (if desirable) changes can be back-ported to drivers/ide/.
>>
> Hello, (drivers/ide) and (drivers/ata) are the two major families, I am working
> on, for generic PM upgradation. I was bit unaware about priority, and also in
> the last, both ide and ata drivers have to be upgraded.

Well, drivers/ide/ is scheduled for removal in 2021
(it even prints the warning during initialization of
every host driver)..

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

>>> All patches are compile-tested only.
>>
>> This patchset needs (at least) some basic testing. It should be easier with
>> libata subsystem as it also support SATA controllers and devices.
> To upgrade PM in (drivers/ide) I have made .suspend() and .resume() static. Then
> bind them in "struct dev_pm_ops" variable (ide_pci_pm_ops) and expose it using
> EXPORT_SYMBOL_GPL(). This has affected 30 drivers. I was hoping if ide changes
> can be tested/verified, specially [PATCH 1/3]. As then, I will be sure about
> similar change in ata, as it also requires similar alteration.
> 
> Thanks
> Vaibhav Gupta
> 
>>
>> Best regards,
>> --
>> Bartlomiej Zolnierkiewicz
>> Samsung R&D Institute Poland
>> Samsung Electronics
>>
>>> v3:
>>>     - Modpost error for undefined reference by Kbuild in v1.
>>>     - Another approach to disable PM in drivers/ide/triflex.c suggested by
>>>       Bjorn Helgaas in v2.
>>>
>>> Test tools:
>>>     - Compiler: gcc (GCC) 10.1.0
>>>     - allmodconfig build: make -j$(nproc) W=1 all
>>>
>>> Vaibhav Gupta (3):
>>>   ide: use generic power management
>>>   ide: sc1200: use generic power management
>>>   ide: delkin_cb: use generic power management
>>>
>>>  drivers/ide/aec62xx.c         |  3 +--
>>>  drivers/ide/alim15x3.c        |  3 +--
>>>  drivers/ide/amd74xx.c         |  3 +--
>>>  drivers/ide/atiixp.c          |  3 +--
>>>  drivers/ide/cmd64x.c          |  3 +--
>>>  drivers/ide/cs5520.c          |  3 +--
>>>  drivers/ide/cs5530.c          |  3 +--
>>>  drivers/ide/cs5535.c          |  3 +--
>>>  drivers/ide/cs5536.c          |  3 +--
>>>  drivers/ide/cy82c693.c        |  3 +--
>>>  drivers/ide/delkin_cb.c       | 32 +++++---------------------
>>>  drivers/ide/hpt366.c          |  3 +--
>>>  drivers/ide/ide-pci-generic.c |  3 +--
>>>  drivers/ide/it8172.c          |  3 +--
>>>  drivers/ide/it8213.c          |  3 +--
>>>  drivers/ide/it821x.c          |  3 +--
>>>  drivers/ide/jmicron.c         |  3 +--
>>>  drivers/ide/ns87415.c         |  3 +--
>>>  drivers/ide/opti621.c         |  3 +--
>>>  drivers/ide/pdc202xx_new.c    |  3 +--
>>>  drivers/ide/pdc202xx_old.c    |  3 +--
>>>  drivers/ide/piix.c            |  3 +--
>>>  drivers/ide/sc1200.c          | 43 ++++++++++++-----------------------
>>>  drivers/ide/serverworks.c     |  3 +--
>>>  drivers/ide/setup-pci.c       | 29 +++++------------------
>>>  drivers/ide/siimage.c         |  3 +--
>>>  drivers/ide/sis5513.c         |  3 +--
>>>  drivers/ide/sl82c105.c        |  3 +--
>>>  drivers/ide/slc90e66.c        |  3 +--
>>>  drivers/ide/triflex.c         | 24 +++++++------------
>>>  drivers/ide/via82cxxx.c       |  3 +--
>>>  include/linux/ide.h           |  8 +------
>>>  32 files changed, 62 insertions(+), 155 deletions(-)
>>>
>>
> 
>