Re: [PATCH 4/4] arm64: dts: renesas: rzv2-evk-cn15-sd: Add ramp delay for SD0 regulator

[Geert Uytterhoeven]

On Sat, 24 Jan 2026 at 00:00, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Set an appropriate ramp delay for the SD0 I/O voltage regulator in the
> CN15 SD overlay to make UHS-I voltage switching reliable during card
> initialization.
>
> This issue was observed on the RZ/V2H EVK, while the same UHS-I cards
> worked on the RZ/V2N EVK without problems. Adding the ramp delay makes
> the behavior consistent and avoids SD init timeouts.
>
> Before this change SD0 could fail with:
> [    2.646242] mmc0: error -110 whilst initialising SD card
>
> With the delay in place UHS-I cards enumerate correctly:
> [    2.633493] mmc0: new UHS-I speed SDR104 SDXC card at address aaaa
> [    2.641687] mmcblk0: mmc0:aaaa SR64G 59.5 GiB
> [    2.651489]  mmcblk0: p1
>
> Fixes: 3d6c2bc7629c8("arm64: dts: renesas: Add CN15 eMMC and SD overlays for RZ/V2H and RZ/V2N EVKs")
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
i.e. will queue in renesas-fixes for v7.0.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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