Re: [PATCH net-next v3 4/9] net: stmmac: qcom-ethqos: fix RGMII_ID mode to use DLL bypass

On Sun, Oct 18, 2026 at 10:47:34AM +0000, netdev-bot+sashiko@kernel.org wrote:

Thank you for your contribution! Sashiko AI review found 3 potential
issue(s) to consider.

Critical: 0 · High: 0 · Medium: 2 · Low: 1

If you believe none of the issues are legitimate, please reply to each
issue of Medium severity or higher and explain why the AI is wrong.
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- [Medium] In rgmii-id mode at 100M and 10M, ethqos_set_clk_tx_rate() now
  calls clk_set_rate(link_clk, 25000000) or clk_set_rate(link_clk,…
- [Medium] net: stmmac: qcom-ethqos: rgmii_setmask() on multi-bit
  RGMII_CONFIG2_RSVD_CONFIG15
- [Low] The commit is titled and described as a fix for a defect in the
  current tree, but it has no Fixes: tag.

--


[Severity: Medium]
Can qcs404 and sc8280xp actually produce 25 MHz and 2.5 MHz on the link
clock?

On qcs404 the "rgmii" link clock is GCC_ETH_RGMII_CLK. Its parent's
frequency table only has these entries:

drivers/clk/qcom/gcc-qcs404.c:ftbl_emac_clk_src
    5 MHz, 50 MHz, 125 MHz, 250 MHz

On sc8280xp it is GCC_EMAC0_RGMII_CLK, and the lowest entry is 50 MHz:

drivers/clk/qcom/gcc-sc8280xp.c:ftbl_gcc_emac0_rgmii_clk_src
    50 MHz, 125 MHz, 250 MHz

Both branch clocks have CLK_SET_RATE_PARENT. The parent RCGs round up
rather than fail:

drivers/clk/qcom/clk-rcg2.c:clk_rcg2_determine_rate() {
	...
	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, CEIL);
}

So in rgmii-id mode at 100M/10M, the request would silently become 50 MHz
or 5 MHz on qcs404, and 50 MHz on sc8280xp. clk_set_rate() would still
return 0.

As mentioned in another reply, I will update the series to use this new
flow for PHY managed RGMII delay for only SoCs that could be validated,
i.e. shikra and qcs615.

	Ayaan

pw-bot: cr