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SubjectRe: [PATCH 0/2] ARM: dts: meson8b/m2: RGMII improvements
Date
On Tue, 12 May 2020 23:51:46 +0200, Martin Blumenstingl wrote:
> the fist patch in this series connects FCLK_DIV2 to the PRG_ETH
> "additional" registers for the dwmac Ethernet controller.
> Now that we know how RGMII and FCLK_DIV2 are connected we can
> add this dependency to get rid of CLK_IS_CRITICAL for FCLK_DIV2
> at some point.
>
> The second patch fixes the RX and TX delay. The 4ns TX delay which
> we have used so far is incorrect and only worked because we were
> using an unsupported clock divider in the PRG_ETH registers. That
> divider has been fixed with commit bd6f48546b9c ("net: stmmac:
> dwmac-meson8b: Fix the RGMII TX delay on Meson8b/8m2 SoCs").
> Instead of "just" fixing the TX delay we can even do better and
> switch to phy-mode = "rgmii-id" to let the PHY generate the RX
> and TX delay. However, previously we didn't know that there was
> an RX delay applied by the MAC on these boards. Only the additional
> information from Jianxin in the other series [0] made us aware
> of this. Without the other series there will be a 4ns RX delay
> (2ns from the MAC and additional 2ns from the PHY). Due to this
> dependency I did not add a Fixes tag, because backporting these
> .dts patches without their runtime dependency will break stable
> kernels.
>
> [...]

Applied, thanks!

[1/2] ARM: dts: meson: Add the Ethernet "timing-adjustment" clock
commit: b632506c5af22a9a7c63674fc605d24cf94d585b
[2/2] ARM: dts: meson: Switch existing boards with RGMII PHY to "rgmii-id"
commit: 005231128e9e97461e81fa32421957a7664317ca

Best regards,
--
Kevin Hilman <khilman@baylibre.com>

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