Re: [PATCH 1/2] arm: dts: renesas: gr-peach: Specify ethernet PHY reset timings
Geert Uytterhoeven <[email protected]>
| Newsgroups | org.kernel.vger.linux-renesas-soc,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <CAMuHMdUaCOFhLrJdzbRRE2PYe2jA=Yiq9KTCRT4i4Sjyj0gnvA@mail.gmail.com> |
On Tue, 14 Jul 2026 at 15:03, Marek Vasut <[email protected]> wrote: > The LAN8710Ai reference manual [1] DS00002164C page 61 FIGURE 5-3: > POWER-ON NRST & CONFIGURATION STRAP TIMING does not indicate how > long should the system wait after deassertion of the PHY reset and > before start of communication with the PHY via MDIO. Opt for 300 us > which should cover every timing option, including the 16 us delay > required for MDIO to switch to 25 MHz listed in Note: in Chapter > 3.8.5 RESETS. > > The LAN8710Ai reference manual [1] DS00002164C page 61 TABLE 5-8: > POWER-ON NRST & CONFIGURATION STRAP TIMING VALUES row tSR Stable > supply voltages to reset high is at minimum 10 ms. Set DT property > reset-assert-us to 25ms because the LAN8710Ai RM does not explicitly > spell out how long the reset has to be asserted, but this at least > covers the worst case scenario. > > [1] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/DataSheets/LAN8710A-LAN8710Ai-Data-Sheet-DS00002164.pdf > > Signed-off-by: Marek Vasut <[email protected]> Reviewed-by: Geert Uytterhoeven <[email protected]> i.e. will queue in renesas-devel for v7.4. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected] In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds