| Message ID | ZOddFH22PWmOmbT5@shell.armlinux.org.uk (mailing list archive) |
|---|---|
| Headers | show |
| Series | stmmac cleanups | expand |
Hello: This series was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 24 Aug 2023 14:37:24 +0100 you wrote: > Hi, > > One of the comments I had on Feiyang Chen's series was concerning the > initialisation of phylink... and so I've decided to do something about > it, cleaning it up a bit. > > This series: > > [...] Here is the summary with links: - [net-next,01/10] net: phylink: add phylink_limit_mac_speed() https://git.kernel.org/netdev/net-next/c/70934c7c99ad - [net-next,02/10] net: stmmac: convert plat->phylink_node to fwnode https://git.kernel.org/netdev/net-next/c/e80af2acdef7 - [net-next,03/10] net: stmmac: clean up passing fwnode to phylink https://git.kernel.org/netdev/net-next/c/1a37c1c19832 - [net-next,04/10] net: stmmac: use "mdio_bus_data" local variable https://git.kernel.org/netdev/net-next/c/2b070cdd3afd - [net-next,05/10] net: stmmac: use phylink_limit_mac_speed() https://git.kernel.org/netdev/net-next/c/a4ac612bd345 - [net-next,06/10] net: stmmac: provide stmmac_mac_phylink_get_caps() https://git.kernel.org/netdev/net-next/c/d42ca04e0448 - [net-next,07/10] net: stmmac: move gmac4 specific phylink capabilities to gmac4 https://git.kernel.org/netdev/net-next/c/f1dae3d222c6 - [net-next,08/10] net: stmmac: move xgmac specific phylink caps to dwxgmac2 core https://git.kernel.org/netdev/net-next/c/bedf9b81233d - [net-next,09/10] net: stmmac: move priv->phylink_config.mac_managed_pm https://git.kernel.org/netdev/net-next/c/64961f1b8ca1 - [net-next,10/10] net: stmmac: convert half-duplex support to positive logic https://git.kernel.org/netdev/net-next/c/76649fc93f09 You are awesome, thank you!
Hi, One of the comments I had on Feiyang Chen's series was concerning the initialisation of phylink... and so I've decided to do something about it, cleaning it up a bit. This series: 1) adds a new phylink function to limit the MAC capabilities according to a maximum speed. This allows us to greatly simplify stmmac's initialisation of phylink's mac capabilities. 2) everywhere that uses priv->plat->phylink_node first converts this to a fwnode before doing anything with it. This is silly. Let's instead store it as a fwnode to eliminate these conversions in multiple places. 3) clean up passing the fwnode to phylink - it might as well happen at the phylink_create() callsite, rather than being scattered throughout the entire function. 4) same for mdio_bus_data 5) use phylink_limit_mac_speed() to handle the priv->plat->max_speed restriction. 6) add a method to get the MAC-specific capabilities from the code dealing with the MACs, and arrange to call it at an appropriate time. 7) convert the gmac4 users to use the MAC specific method. 8) same for xgmac. 9) group all the simple phylink_config initialisations together. 10) convert half-duplex logic to being positive logic. While looking into all of this, this raised eyebrows: if (priv->plat->tx_queues_to_use > 1) priv->phylink_config.mac_capabilities &= ~(MAC_10HD | MAC_100HD | MAC_1000HD); priv->plat->tx_queues_to_use is initialised by platforms to either 1, 4 or 8, and can be controlled from userspace via the --set-channels ethtool op. The implementation of this op in this driver limits the number of channels to priv->dma_cap.number_tx_queues, which is derived from the DMA hwcap. So, the obvious questions are: 1) what guarantees that the static initialisation of tx_queues_to_use will always be less than or equal to number_tx_queues from the DMA hw cap? 2) tx_queues_to_use starts off as 1, but number_tx_queues is larger, we will leave the half-duplex capabilities in place, but userspace can increase tx_queues_to_use above 1. Does that mean half-duplex is then not supported? 3) Should we be basing the decision whether half-duplex is supported off the DMA capabilities? 4) What about priv->dma_cap.half_duplex? Doesn't that get a say in whether half-duplex is supported or not? Why isn't this used? Why is it only reported via debugfs? If it's not being used by the driver, what's the point of reporting it via debugfs? drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 8 +++ .../net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 10 ++++ drivers/net/ethernet/stmicro/stmmac/hwif.h | 4 ++ drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 60 +++++++++------------- drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 3 +- .../net/ethernet/stmicro/stmmac/stmmac_platform.c | 2 +- drivers/net/phy/phylink.c | 18 +++++++ include/linux/phylink.h | 2 + include/linux/stmmac.h | 2 +- 9 files changed, 70 insertions(+), 39 deletions(-)