[EXT] Re: [PATCH v2 net 2/2] net: stmmac: dwmac-imx: pause the TXC clock in fixed-link

[Shenwei Wang]

> -----Original Message-----
> From: Fabio Estevam <festevam at gmail.com>
> Sent: Friday, July 28, 2023 6:01 AM
> To: Shenwei Wang <shenwei.wang at nxp.com>; Andrew Lunn <andrew at lunn.ch>
> Cc: Russell King <linux at armlinux.org.uk>; David S. Miller
> <davem at davemloft.net>; Eric Dumazet <edumazet at google.com>; Jakub
> Kicinski <kuba at kernel.org>; Paolo Abeni <pabeni at redhat.com>; Maxime
> Coquelin <mcoquelin.stm32 at gmail.com>; Shawn Guo <shawnguo at kernel.org>;
> Sascha Hauer <s.hauer at pengutronix.de>; Neil Armstrong
> <neil.armstrong at linaro.org>; Kevin Hilman <khilman at baylibre.com>; Vinod
> Koul <vkoul at kernel.org>; Chen-Yu Tsai <wens at csie.org>; Jernej Skrabec
> <jernej.skrabec at gmail.com>; Samuel Holland <samuel at sholland.org>;
> Giuseppe Cavallaro <peppe.cavallaro at st.com>; Alexandre Torgue
> <alexandre.torgue at foss.st.com>; Jose Abreu <joabreu at synopsys.com>;
> Pengutronix Kernel Team <kernel at pengutronix.de>; dl-linux-imx <linux-
> 
> 
> On Thu, Jul 27, 2023 at 12:25 PM Shenwei Wang <shenwei.wang at nxp.com>
> wrote:
> 
> >         struct plat_stmmacenet_data *plat_dat = priv; @@ -317,8
> > +359,11 @@ static int imx_dwmac_probe(struct platform_device *pdev)
> >         plat_dat->exit = imx_dwmac_exit;
> >         plat_dat->clks_config = imx_dwmac_clks_config;
> >         plat_dat->fix_mac_speed = imx_dwmac_fix_speed;
> > +       if (of_machine_is_compatible("fsl,imx93"))
> > +               plat_dat->fix_mac_speed = imx_dwmac_fix_speed_mx93;
> 
> So you are forcing this on all imx93 boards, even if they don't use a SJA1105.
> 

Yes, that's the purpose because it won't hurt even the other side is not SJA1105.

> Andrew Lunn gave the following feedback in v1:
> 
> "The SJA1105 has the problem, so i would expect it to be involved in the solution.
> Otherwise, how is this going to work for other MAC drivers?
> 
> Maybe you need to expose a common clock framework clock for the TXC clock
> line, which the SJA1105 can disable/enable? That then makes it clear what other
> MAC drivers need to do."

I have been considering this plan for some time. The idea should be implemented 
across all i.mx8/9 platforms. I am going to start to work on it in the following month, 
and it will take some time to implement it.

Thanks,
Shenwei