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Message-ID: <3c98ea6c-b80f-59d4-ad84-85cf1c9ff440@v0yd.nl>
Date:   Tue, 12 Oct 2021 13:20:46 +0200
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Subject: Re: [PATCH] mwifiex: Add quirk resetting the PCI bridge on MS Surface
 devices
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To:     =?UTF-8?Q?Pali_Roh=c3=a1r?= <pali@kernel.org>
Cc:     Bjorn Helgaas <helgaas@kernel.org>,
        Amitkumar Karwar <amitkarwar@gmail.com>,
        Ganapathi Bhat <ganapathi017@gmail.com>,
        Xinming Hu <huxinming820@gmail.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Tsuchiya Yuto <kitakar@gmail.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
        Maximilian Luz <luzmaximilian@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        Brian Norris <briannorris@chromium.org>,
        David Laight <David.Laight@ACULAB.COM>,
        Alex Williamson <alex.williamson@redhat.com>
References: <20211011165301.GA1650148@bhelgaas>
 <fee8b431-617f-3890-3ad2-67a61d3ffca2@v0yd.nl>
 <20211012090037.v3w4za5hshtm253f@pali>
From:   =?UTF-8?Q?Jonas_Dre=c3=9fler?= <verdre@v0yd.nl>
In-Reply-To: <20211012090037.v3w4za5hshtm253f@pali>
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On 10/12/21 11:00, Pali Rohár wrote:
> On Tuesday 12 October 2021 10:48:49 Jonas Dreßler wrote:
>> 1) Revert the cards firmware in linux-firmware back to the second-latest
>> version. That firmware didn't report a fixed LTR value and also doesn't
>> have any other obvious issues I know of compared to the latest one.
> 
> FYI, there are new bugs with new firmware versions for 8997 sent by NXP
> to linux-firmware repository... and questions what to do with it. Seems
> that NXP again do not respond to any questions after new version was
> merged into linux-firmware repo.
> 
> https://lore.kernel.org/linux-firmware/edeb34bc-7c85-7f1d-79e4-e3e21df86334@gk2.net/
> 
> So firmware revert also for other ex-Marvell / NXP chips is not
> something which could not happen.
> 

Argh, nevermind, it seems like my memory is fooling me once again, sorry.
I just tried the older firmware and I was completely wrong, there's no
difference at all between the versions when it comes to LTR messages. So
there goes alternative 1).

Something interesting and reassuring I noticed though: After resuming from
suspend the firmware actually doesn't send a new LTR message, which means
now the LTR is 0 and we enter PC10/S0ix just fine. So basically the change
this patch does is already in effect, just after one suspend/resume cycle.
That gives me more confidence that we should maybe apply this patch for
all 8897 devices, not only Surface devices?