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Date:   Mon, 5 Dec 2022 17:44:41 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Lorenzo Bianconi <lorenzo@kernel.org>
Cc:     Leon Romanovsky <leon@kernel.org>, netdev@vger.kernel.org,
        nbd@nbd.name, john@phrozen.org, sean.wang@mediatek.com,
        Mark-MC.Lee@mediatek.com, davem@davemloft.net, edumazet@google.com,
        pabeni@redhat.com, matthias.bgg@gmail.com,
        linux-mediatek@lists.infradead.org, lorenzo.bianconi@redhat.com
Subject: Re: [PATCH net-next] net: ethernet: mtk_wed: fix possible deadlock
 if mtk_wed_wo_init fails
Message-ID: <20221205174441.30741550@kernel.org>
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On Mon, 5 Dec 2022 10:04:07 +0100 Lorenzo Bianconi wrote:
> > IMHO, it is a culprit, proper error unwind means that you won't call to
> > uninit functions for something that is not initialized yet. It is better
> > to fix it instead of adding "if (!wo) ..." checks.  
> 
> So, iiuc, you would prefer to do something like:
> 
> __mtk_wed_detach()
> {
> 	...
> 	if (mtk_wed_get_rx_capa(dev) && wo) {
> 		mtk_wed_wo_reset(dev);
> 		mtk_wed_free_rx_rings(dev);
> 		mtk_wed_wo_deinit(hw);
> 	}
> 	...
> 	
> Right? I am fine both ways :)

FWIW, that does seem slightly better to me as well.
Also - aren't you really fixing multiple issues here 
(even if on the same error path)? The locking, 
the null-checking and the change in mtk_wed_wo_reset()?