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Subject: Re: [PATCH v2] PCI: dra7xx: Fix reset behaviour
To:     =?UTF-8?Q?Pali_Roh=c3=a1r?= <pali@kernel.org>
Cc:     Kishon Vijay Abraham I <kishon@ti.com>, linux-pci@vger.kernel.org,
        linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>
References: <20210531090540.2663171-1-luca@lucaceresoli.net>
 <20210531133211.llyiq3jcfy25tmz4@pali>
 <8ff1c54f-bb29-1e40-8342-905e34361e1c@lucaceresoli.net>
 <9fdbada4-4902-cec1-f283-0d12e1d4ac64@ti.com>
 <20210531162242.jm73yzntzmilsvbg@pali>
 <8207a53c-4de9-d0e5-295a-c165e7237e36@lucaceresoli.net>
 <20210622110627.aqzxxtf2j3uxfeyl@pali>
From:   Luca Ceresoli <luca@lucaceresoli.net>
Message-ID: <58aaadb4-c643-76ce-bda0-294bb2300137@lucaceresoli.net>
Date:   Tue, 22 Jun 2021 23:13:38 +0200
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Hi Pali,

On 22/06/21 13:06, Pali Rohár wrote:
> Hello!
> 
> On Tuesday 22 June 2021 12:57:22 Luca Ceresoli wrote:
>> Nothing happened after a few weeks... I understand that knowing the
>> correct reset timings is relevant, but unfortunately I cannot help much
>> in finding out the correct values.
>>
>> However I'm wondering what should happen to this patch. It *does* fix a
>> real bug, but potentially with an incorrect or non-optimal usleep range.
>> Do we really want to ignore a bugfix because we are not sure about how
>> long this delay should be?
> 
> As there is no better solution right now, I'm fine with your patch. But
> patch needs to be approved by Lorenzo, so please wait for his final
> answer.
> 
> I would suggest to add a comment for call "usleep_range(1000, 2000);"
> that you have chosen some "random" values which worked fine on your
> setup and that they fix mentioned bug. Comment just to mark this sleep
> code that is suboptimal / not-so-correct and to prevent other people to
> copy+paste this code into other (new) drivers...

Sure, good idea.

I'm following this thread and will send v3 after a direction is agreed upon.

-- 
Luca