From mboxrd@z Thu Jan  1 00:00:00 1970
From: marc.zyngier@arm.com (Marc Zyngier)
Date: Tue, 30 Oct 2018 14:55:01 +0000
Subject: [BUG] MVPP2 driver exploding in presence of a tap interface
In-Reply-To: <20181030140056.2fc69efc@windsurf>
References: <6355174d-4ab6-595d-17db-311bce607aef@arm.com>
 <20181030105015.GB3407@kwain> <7bd72963-1e7c-5175-ba88-fc020d786f0c@arm.com>
 <CAPv3WKfn6QFPnNjpY2dU5-OHftObzdcrHopX8Y9w5h37Zd4BNw@mail.gmail.com>
 <20181030140056.2fc69efc@windsurf>
Message-ID: <6bf82e04-5463-aa7d-bbac-f09519ff9815@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 30/10/18 13:00, Thomas Petazzoni wrote:
> Hello Marcin,
> 
> Thanks for the feedback.
> 
> On Tue, 30 Oct 2018 13:37:37 +0100, Marcin Wojtas wrote:
> 
>> You use _really_ archaic firmware, the bug you see is 99% caused by a
>> bug already fixed long time ago (cleanup all PP2 BM pools correctly
>> during exit boot services). Please grab the latest release:
>> https://github.com/MarvellEmbeddedProcessors/edk2-open-platform/wiki/files/flash-image-18.09.4.bin
>> and let know if you observe any further issues with vanilla kernel.
> 
> Even if this was a bug in the UEFI firmware, shouldn't the kernel be
> independent from that, by doing a proper reset/reinit of the HW ?
> 
> I.e, isn't the firmware fix papering over a bug that should be fixed in
> Linux mvpp2 driver anyway ?

Absolutely. Leaving this unpatched in the kernel, with a 100% chance of
memory corruption is just mad.

I'm pretty sure there should be a way to sanely reset the interface
before it starts repainting the memory. And if there is none, we must
find a way to tell the user that the machine is a death trap. Really.

	M.

PS: updating the FW to the version provided by Marcin indeed makes
things much more reliable. Thanks for that.
-- 
Jazz is not dead. It just smells funny...