On Mon, May 27, 2024 at 12:57:02AM +0300, Serge Semin wrote: > On Sun, May 26, 2024 at 05:49:48PM +0100, Russell King (Oracle) wrote: > > On Sat, May 25, 2024 at 12:02:58AM +0300, Serge Semin wrote: > > > 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. > > > > > Thanks. As this is a fix, shouldn't it be submitted for the net tree as > > it seems to be fixing a bug in the driver as it stands today? > > From one point of view it could be submitted for the net tree indeed, > but on the second thought are you sure we should be doing that seeing > it will activate the RGMII-inband detection and the code with the > netif-carrier toggling behind the phylink back? Who knows what new > regressions the activated PCS-code can cause?.. If it's not a fix that is suitable without the remainder of the patch set, this should be stated in the commit description and it shouldn't have a Fixes: tag. The reason is because it wouldn't be stable kernel material without the other patches - if stable picks it up without the other patches then it could end up being applied without the other patches resulting in the situation you mention above. Shall I remove the Fixes: tag? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
