Re: [PATCH net-next] net: stmmac: dwmac-renesas-gbeth: Add PM suspend/resume callbacks

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Sun, Jul 06, 2025 at 09:55:28AM +0000, Biju Das wrote:
> Just adding some logs:
> Currently PHY resume is called twice
> [   35.754933]  kszphy_resume+0x3c/0xf0
> [   35.754940]  phy_resume+0x3c/0x74
> [   35.754949]  phylink_prepare_resume+0x58/0xa0
> [   35.754957]  stmmac_resume+0x90/0x2a0
> [   35.771296]  stmmac_pltfr_resume+0x3c/0x4c
> 
> and
> 
> [   35.771258]  kszphy_resume+0x3c/0xf0
> [   35.771263]  __phy_resume+0x28/0x54
> [   35.771270]  phy_start+0x7c/0xb4
> [   35.771275]  phylink_start+0xb8/0x210
> [   35.771282]  phylink_resume+0x7c/0xc4
> [   35.771288]  stmmac_resume+0x1ec/0x2a0
> [   35.771296]  stmmac_pltfr_resume+0x3c/0x4c

This shouldn't be a problem. Phylib will do this, and PHY drivers are
expected to cope.

For example, on non-MAC managed PM PHYs, mdio_bus_phy_resume() will
call phy_init_hw() followed by phy_resume(). If a MAC subsequently is
brought up, phy_start() will be called, which will also call
__phy_resume().

If this is upsetting the KSZ PHY, then the KSZ PHY driver needs fixing.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!