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Date: Wed, 28 Jun 2023 14:06:12 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Shannon Nelson <shannon.nelson@amd.com>
Cc: "Keller, Jacob E" <jacob.e.keller@intel.com>, "netdev@vger.kernel.org"
 <netdev@vger.kernel.org>, "davem@davemloft.net" <davem@davemloft.net>,
 "brett.creeley@amd.com" <brett.creeley@amd.com>, "drivers@pensando.io"
 <drivers@pensando.io>, "nitya.sunkad@amd.com" <nitya.sunkad@amd.com>
Subject: Re: [PATCH net] ionic: remove WARN_ON to prevent panic_on_warn
Message-ID: <20230628140612.4736ed58@kernel.org>
In-Reply-To: <1b33f325-c104-8b0c-099f-f2d2e98fed66@amd.com>
References: <20230628170050.21290-1-shannon.nelson@amd.com>
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On Wed, 28 Jun 2023 11:26:18 -0700 Shannon Nelson wrote:
> > This message could potentially use a bit more explanation since it
> > doesn't look like you removed all the WARN_ONs in the driver, and
> > it might help to explain why this particular WARN_ON was
> > problematic. I don't think that would be worth a re-roll on its own
> > though.  
> 
> There has been recent mention of not using WARNxxx macros because so 
> many folks have been setting panic_on_warn [1].  This is intended to 
> help mitigate the possibility of unnecessarily killing a machine when
> we can adjust and continue.
> [1]:
> https://lore.kernel.org/netdev/2023060820-atom-doorstep-9442@gregkh/
> 
> I believe the only other WARNxxx in this driver is a WARN_ON_ONCE in 
> ionic_regs.h which can be addressed in a separate patch.
> 
> Neither of these are ever expected to be hit, but also neither should 
> ever kill a machine.

An explanation that this warning may in fact be hit and how in 
the commit message would be good.