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

From: Andrew Lunn
Date: Fri Feb 04 2022 - 08:10:47 EST


On Fri, Feb 04, 2022 at 05:29:11AM +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.

Hi Pavel

There appears to be another path which has the same issue.

m88e1118_config_aneg() calls marvell_set_polarity(), which also needs
a reset afterwards.

Could you fix this case as well?

Thanks
Andrew