[PATCH net-next 14/14] net: stmmac: Activate Inband/PCS flag based on the selected iface

[Andrew Halaney]

On Fri, Aug 02, 2024 at 11:47:37AM GMT, Russell King wrote:
> From: Serge Semin <fancer.lancer at gmail.com>
> 
> The HWFEATURE.PCSSEL flag is set if the PCS block has been synthesized
> into the DW GMAC controller. It's always done if the controller supports
> at least one of the SGMII, TBI, RTBI PHY interfaces. If none of these
> interfaces support was activated during the IP-core synthesize the PCS
> block won't be activated either and the HWFEATURE.PCSSEL flag won't be
> set. Based on that the RGMII in-band status detection procedure
> implemented in the driver hasn't been working for the devices with the
> RGMII interface support and with none of the SGMII, TBI, RTBI PHY
> interfaces available in the device.
> 
> Fix that just by dropping the dma_cap.pcs flag check from the conditional
> statement responsible for the In-band/PCS functionality activation. If the
> RGMII interface is supported by the device then the in-band link status
> detection will be also supported automatically (it's always embedded into
> the RGMII RTL code). If the SGMII interface is supported by the device
> then the PCS block will be supported too (it's unconditionally synthesized
> into the controller). The later is also correct for the TBI/RTBI PHY
> interfaces.
> 
> Note while at it drop the netdev_dbg() calls since at the moment of the
> stmmac_check_pcs_mode() invocation the network device isn't registered. So
> the debug prints will be for the unknown/NULL device.
> 
> Signed-off-by: Serge Semin <fancer.lancer at gmail.com>
> [rmk: fix build errors, only use PCS for SGMII if priv->dma_cap.pcs is set]
> Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>

Russell, did you add in the priv->dma_cap.pcs check with SGMII just
because it *is* expected to be set unconditionally when SGMII support is
there?

Always fan of less conditionals, so just curious as to your motivation
since Serge's message makes it seem like SGMII && dma_cap.pcs is a
redundant check.

Otherwise, looks good to me.

Thanks,
Andrew