Re: [PATCH] net: phy: marvell: Fix RGMII Tx/Rx delays setting in 88e1121-compatible PHYs

From: Jakub Kicinski
Date: Fri Feb 04 2022 - 23:03:13 EST


On Fri, 4 Feb 2022 05:29:11 +0000
Pavel.Parkhomenko@xxxxxxxxxxxxxxxxxxxx wrote:
> It is mandatory for a software to issue a reset upon modifying RGMII
> Receive Timing Control and RGMII Transmit Timing Control bit fields of MAC
> Specific Control register 2 (page 2, register 21) otherwise the changes
> won't be perceived by the PHY (the same is applicable for a lot of other
> registers). Not setting the RGMII delays on the platforms that imply
> it's being done on the PHY side will consequently cause the traffic loss.
> We discovered that the denoted soft-reset is missing in the
> m88e1121_config_aneg() method for the case if the RGMII delays are
> modified but the MDIx polarity isn't changed or the auto-negotiation is
> left enabled, thus causing the traffic loss on our platform with Marvell
> Alaska 88E1510 installed. Let's fix that by issuing the soft-reset if the
> delays have been actually set in the m88e1121_config_aneg_rgmii_delays()
> method.
>
> Fixes: d6ab93364734 ("net: phy: marvell: Avoid unnecessary soft reset")
> Signed-off-by: Pavel Parkhomenko <Pavel.Parkhomenko@xxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
> Cc: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx

Appears not to apply to net, please rebase on top of:

https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/

and repost (do keep Russell's tag and address Andrew's question).