Re: MT7922 problem with "fix rx filter incorrect by drv/fw inconsistent"

From: Thorsten Leemhuis <regressions@leemhuis.info>
To: Kalle Valo <kvalo@kernel.org>
Cc: Andrey Rakhmatullin <wrar@wrar.name>,
	Linux regressions mailing list <regressions@lists.linux.dev>,
	linux-wireless@vger.kernel.org, Neil Chen <yn.chen@mediatek.com>,
	Deren Wu <deren.wu@mediatek.com>,
	Lorenzo Bianconi <lorenzo@kernel.org>,
	Felix Fietkau <nbd@nbd.name>,
	AngeloGioacchino Del Regno
	<angelogioacchino.delregno@collabora.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	netdev <netdev@vger.kernel.org>
Subject: Re: MT7922 problem with "fix rx filter incorrect by drv/fw inconsistent"
Date: Mon, 19 Jun 2023 14:48:59 +0200	[thread overview]
Message-ID: <e3af69f2-d3e5-8039-c6e5-5b00fe066cc0@leemhuis.info> (raw)
In-Reply-To: <87jzw8g8hk.fsf@kernel.org>

On 12.06.23 14:39, Kalle Valo wrote:
> Thorsten Leemhuis <regressions@leemhuis.info> writes:
>> On 22.05.23 16:12, Thorsten Leemhuis wrote:
>>> On 22.05.23 15:20, Andrey Rakhmatullin wrote:
>>>> On Mon, May 22, 2023 at 03:00:30PM +0200, Linux regression tracking
>>>> #adding (Thorsten Leemhuis) wrote:
>>>>> On 18.05.23 16:39, Andrey Rakhmatullin wrote:
>>>> I updated the firmware and now the problem doesn't happen.
>>>> The firmware where the problem happens is
>>>> mediatek/WIFI_RAM_CODE_MT7922_1.bin from the linux-firmware commit
>>>> e2d11744ef (file size 826740, md5sum 8ff1bdc0f54f255bb2a1d6825781506b),
>>>> the one where the problem doesn't happen is from the commit 6569484e6b
>>>> (file size 827124, md5sum 14c08c8298b639ee52409b5e9711a083).
>>> FWIW, just checked: that commit is from 2023-05-15, so quite recent.
>>>
>>>> I haven't
>>>> tried the version committed between these ones.
>>>> Not sure if this should be reported to regzbot and if there are any
>>>> further actions needed by the kernel maintainers.
>>>
>>> Well, to quote the first sentence from
>>> Documentation/driver-api/firmware/firmware-usage-guidelines.rst
>>>
>>> ```Users switching to a newer kernel should *not* have to install newer
>>> firmware files to keep their hardware working.```
>>>
>>> IOW: the problem you ran into should not happen. This afaics makes it a
>>> regression that needs to be addressed -- at least if it's something that
>>> is likely to hit others users as well. But I'd guess that's the case.
>>
>> Well, until now I didn't see any other report about a problem like this.
>> Maybe things work better for others with that hardware – in that case it
>> might be something not worth making a fuzz about. But I'll wait another
>> week or two before I remove this from the tracking.
> 
> Yeah, this is bad. mt76 (or any other wireless driver) must not require
> a new firmware whenever upgrading the kernel. Instead the old and new
> firmware should coexist (for example have firmware-2.bin for the new
> version and firmware.bin for the old version). Then mt76 should first
> try loading the new firmware (eg. firmware-2.bin) and then try the old
> one (eg. firmware.bin).
> 
> Should we revert commit c222f77fd4 or how to solve this?

I had hoped someone would rely with an opinion on this, but nobody did
(and the reporter didn't reply to Lorenzo inquiry). So if you asked for
mine:

Hmmm. Tricky. This was the only such report I noticed. Giving that and
the risk that a revert might cause regressions on its own, I guess it
might be better to leave everything as it is for now - and re-evaluate
the situation in case more problems show up.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
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