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Message-ID: <830324ea-7fdb-4769-a1c7-08d59905ca4b@bootlin.com>
Date: Wed, 24 Jan 2024 15:09:56 +0100
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Subject: Re: [PATCH 14/14] PCI: j721e: add suspend and resume support
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
 Bartosz Golaszewski <brgl@bgdev.pl>, Andy Shevchenko <andy@kernel.org>,
 Tony Lindgren <tony@atomide.com>, Haojian Zhuang
 <haojian.zhuang@linaro.org>, Vignesh R <vigneshr@ti.com>,
 Aaro Koskinen <aaro.koskinen@iki.fi>,
 Janusz Krzysztofik <jmkrzyszt@gmail.com>, Andi Shyti
 <andi.shyti@kernel.org>, Peter Rosin <peda@axentia.se>,
 Vinod Koul <vkoul@kernel.org>, Kishon Vijay Abraham I <kishon@kernel.org>,
 Philipp Zabel <p.zabel@pengutronix.de>, Tom Joseph <tjoseph@cadence.com>,
 Lorenzo Pieralisi <lpieralisi@kernel.org>,
 =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>,
 Rob Herring <robh@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>,
 linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
 linux-i2c@vger.kernel.org, linux-phy@lists.infradead.org,
 linux-pci@vger.kernel.org, gregory.clement@bootlin.com,
 theo.lebrun@bootlin.com, thomas.petazzoni@bootlin.com, u-kumar1@ti.com
References: <20240102-j7200-pcie-s2r-v1-0-84e55da52400@bootlin.com>
 <20240102-j7200-pcie-s2r-v1-14-84e55da52400@bootlin.com>
 <CAHp75VfPQz4PWdzFUU_n+R=XohBjyXM0zsjD-bUD2jmb42ds8Q@mail.gmail.com>
 <9cb47f37-bd98-4136-b844-33cf2be593df@bootlin.com>
 <CAHp75Ve30T3t0_vHR7TUVVC_WN23dL_rp1k951Da6Re2DJQezw@mail.gmail.com>
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From: Thomas Richard <thomas.richard@bootlin.com>
In-Reply-To: <CAHp75Ve30T3t0_vHR7TUVVC_WN23dL_rp1k951Da6Re2DJQezw@mail.gmail.com>
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On 1/22/24 22:36, Andy Shevchenko wrote:
> On Mon, Jan 22, 2024 at 5:30 PM Thomas Richard
> <thomas.richard@bootlin.com> wrote:
>> On 1/15/24 21:13, Andy Shevchenko wrote:
>>> On Mon, Jan 15, 2024 at 6:16 PM Thomas Richard
>>> <thomas.richard@bootlin.com> wrote:
> 
> ...
> 
>>>> +               if (pcie->reset_gpio)
>>>
>>> Dup, why?
>>
>> This pcie->reset_gpio corresponds to PERST# of PCIe endpoints.
>> I assert it during suspend, because I have to deassert it (with a delay)
>> during resume stage [1].
> 
> Ah, sorry for being unclear, I meant that gpiod_set_value*() already
> has that check, you don't need it here.

ok understood, check is useless.

> 
>>>> +                       gpiod_set_value_cansleep(pcie->reset_gpio, 0);
> 
> ...
> 
>>>> +               if (pcie->reset_gpio) {
>>>> +                       usleep_range(100, 200);
>>>
>>> fsleep() ?
>>> Btw, why is it needed here, perhaps a comment?
>>
>> The comment should be the same than in the probe [1].
>> Should I copy it? Or should I just add a reference to the probe?
>>
>> [1]
>> https://elixir.bootlin.com/linux/v6.8-rc1/source/drivers/pci/controller/cadence/pci-j721e.c#L535
> 
> Either way works for me.
> 
>>>> +                       gpiod_set_value_cansleep(pcie->reset_gpio, 1);
>>>> +               }
> 
> ...
> 
>>>> +#define cdns_pcie_to_rc(p) container_of(p, struct cdns_pcie_rc, pcie)
>>>
>>> Is container_of.h included in this file?
>>
>> linux/container_of.h is included in linux/kernel.h.
>> And linux/kernel.h is included in pcie-cadence.h
>> (https://elixir.bootlin.com/linux/v6.8-rc1/source/drivers/pci/controller/cadence/pcie-cadence.h#L9).
> 
> Okay, so, try to clean up pcie-cadence.h so it won't use "proxy" headers.
> There is an IWYU (include what you use) principle, please follow it.

In fact, as cdns_pcie_to_rc is only used in pci-j721e.c, no need to have
it in a header file.
I prefer to move cdns_pcie_to_rc definition in pci-j721e.c.
As I don't modify pcie-cadence.h, the cleanup to not use proxy headers
is something that it can be done outside this series.

-- 
Thomas Richard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com