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Message-ID: <5968a30f-bf5c-47b7-be2d-71d8dd18699b@astralinux.ru>
Date: Thu, 21 Mar 2024 15:06:30 +0300
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Subject: Re: [PATCH] net: dsa: add return value check of genphy_read_status()
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To: Florian Fainelli <f.fainelli@gmail.com>, Andrew Lunn <andrew@lunn.ch>
Cc: Vladimir Oltean <olteanv@gmail.com>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>,
 Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
 Sebastian Reichel <sre@kernel.org>, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org
References: <20240314063008.11214-1-adiupina@astralinux.ru>
 <99631ba3-36f9-4eed-80d9-4a663ef46d80@lunn.ch>
 <bb752899-dbf3-4dd2-89f0-d280488bd8bf@astralinux.ru>
 <05a042d5-95fa-4eff-b2ad-c26e865837b1@gmail.com>
From: Alexandra Diupina <adiupina@astralinux.ru>
In-Reply-To: <05a042d5-95fa-4eff-b2ad-c26e865837b1@gmail.com>
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21/03/24 02:48, Florian Fainelli пишет:
>
>
> On 15/03/2024 03:25, Александра Дюпина wrote:
>> Hello, Andrew!
>
> (please do not top-post)
>
>>
>> The dsa_register_switch() function is used in various DSA
>> drivers (in probe function), so it is necessary to check all
>> possible errors. If the return value (may be an error code)
>> of genphy_read_status() is not checked in
>> dsa_shared_port_fixed_link_register_of(), a possible error
>> in dsa_register_switch() may be missed.
>
> This is not a path that will fail, because the fixed PHY emulation 
> layer is not a real piece of hardware, therefore no MDIO read could 
> really cause a problem here. I don't have a strong opinion however if 
> you want to propagate it properly.

Hi, Florian!
I would like to make sure that I have understood you correctly. Checking 
the return value of genphy_read_status() in 
dsa_shared_port_fixed_link_register_of() is not needed because 
dsa_shared_port_fixed_link_register_of() is called if 
of_phy_is_fixed_link()==true (this means that the PHY emulation layer is 
used, link is registered by of_phy_register_fixed_link() without errors 
and therefore there cannot be an error in genphy_read_status()). Right?