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Message-ID: <8c43b018-8979-e93b-cc19-76de6f8b60d1@gmail.com>
Date:   Fri, 20 Jan 2023 10:12:01 -0800
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Subject: Re: [PATCH net v2] net: dsa: microchip: fix probe of I2C-connected
 KSZ8563
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To:     Ahmad Fatoum <a.fatoum@pengutronix.de>,
        Jakub Kicinski <kuba@kernel.org>,
        Woojung Huh <woojung.huh@microchip.com>,
        UNGLinuxDriver@microchip.com, Andrew Lunn <andrew@lunn.ch>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Oleksij Rempel <linux@rempel-privat.de>
Cc:     kernel@pengutronix.de, ore@pengutronix.de,
        Arun.Ramadoss@microchip.com, Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230120110933.1151054-1-a.fatoum@pengutronix.de>
From:   Florian Fainelli <f.fainelli@gmail.com>
In-Reply-To: <20230120110933.1151054-1-a.fatoum@pengutronix.de>
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On 1/20/2023 3:09 AM, Ahmad Fatoum wrote:
> Starting with commit eee16b147121 ("net: dsa: microchip: perform the
> compatibility check for dev probed"), the KSZ switch driver now bails
> out if it thinks the DT compatible doesn't match the actual chip ID
> read back from the hardware:
> 
>    ksz9477-switch 1-005f: Device tree specifies chip KSZ9893 but found
>    KSZ8563, please fix it!
> 
> For the KSZ8563, which used ksz_switch_chips[KSZ9893], this was fine
> at first, because it indeed shares the same chip id as the KSZ9893.
> 
> Commit b44908095612 ("net: dsa: microchip: add separate struct
> ksz_chip_data for KSZ8563 chip") started differentiating KSZ9893
> compatible chips by consulting the 0x1F register. The resulting breakage
> was fixed for the SPI driver in the same commit by introducing the
> appropriate ksz_switch_chips[KSZ8563], but not for the I2C driver.
> 
> Fix this for I2C-connected KSZ8563 now to get it probing again.
> 
> Fixes: b44908095612 ("net: dsa: microchip: add separate struct ksz_chip_data for KSZ8563 chip").
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian