Re: [PATCHv2 1/2] ARM: dts: imx6sx: Use MX6SX_CLK_ENET for fec 'ahb' clock

From: Fabio Estevam
Date: Tue May 07 2019 - 19:10:50 EST


Hi Andy,

On Sun, May 5, 2019 at 5:15 AM Andy Duan <fugang.duan@xxxxxxx> wrote:

> Nack the patch !
>
> Firstly, i.MX6SX has ENET AHB bus clock for MAC, and currently it is set 200Mhz like clock tree:
> IMX6SX_CLK_ENET_PODF 200Mhz -> IMX6SX_CLK_ENET_SEL -> IMX6SX_CLK_ENET_AHB
>
> IMX6SX_CLK_ENET the clock is IPG clock for ENET IP ipg_clk_mac0_s/ipg_clk_s.
> (Please check RM Table 18-3. System Clocks, Gating, and Override)

Ok, but could you please show us where in the Reference Manual the
IMX6SX_CLK_ENET_AHB is mentioned?

I don't see ENET_AHB in imx6qdl Reference Manual either and we don't
have a ENET_AHB the clk-imx6q driver and nor in the devicetree,

> Secondly, for your issue you caught, which was fixed by patch:
> commit d7c3a206e6338e4ccdf030719dec028e26a521d5
> Author: Andy Duan <fugang.duan@xxxxxxx>
> Date: Tue Apr 9 03:40:56 2019 +0000
>
> net: fec: manage ahb clock in runtime pm

Would this also fix the case where power management support is disabled?

If I understand correctly the explanation from Kay-Liu he would still
see a hang in the case when PM is disabled.

Thanks