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Date: Tue, 27 Feb 2024 18:17:09 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Javier Carrasco <javier.carrasco.cruz@gmail.com>, Andrew Lunn
 <andrew@lunn.ch>
Cc: Peter Korsgaard <peter@korsgaard.com>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Paolo Abeni
 <pabeni@redhat.com>, netdev@vger.kernel.org, linux-usb@vger.kernel.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: usb: dm9601: fix wrong return value in
 dm9601_mdio_read
Message-ID: <20240227181709.7159d60f@kernel.org>
In-Reply-To: <20240225-dm9601_ret_err-v1-1-02c1d959ea59@gmail.com>
References: <20240225-dm9601_ret_err-v1-1-02c1d959ea59@gmail.com>
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On Sun, 25 Feb 2024 00:20:06 +0100 Javier Carrasco wrote:
> The MII code does not check the return value of mdio_read (among
> others), and therefore no error code should be sent. A previous fix to
> the use of an uninitialized variable propagates negative error codes,
> that might lead to wrong operations by the MII library.
> 
> An example of such issues is the use of mii_nway_restart by the dm9601
> driver. The mii_nway_restart function does not check the value returned
> by mdio_read, which in this case might be a negative number which could
> contain the exact bit the function checks (BMCR_ANENABLE = 0x1000).
> 
> Return zero in case of error, as it is common practice in users of
> mdio_read to avoid wrong uses of the return value.

A bit odd but appears to be true, so I'll apply, thank you!

Andrew, 
mii.h files seem to fall under PHYLIB in MAINTAINERS, but mii.c does
not. Is this intentional?