Re: [PATCH v2 RESEND 3/6] mmc: rtsx_usb_sdmmc: advertise UHS SDR104 and DDR50

[Ulf Hansson]

On Thu, 12 Mar 2026 at 13:16, Sean Rhodes <sean@starlabs.systems> wrote:
>
> The rtsx_usb_sdmmc driver already implements UHS-I voltage switching,
> timing setup and tuning, but it only advertises support up to SDR50.
>
> Like the old rts5139 driver, also advertise SDR104 and DDR50 so the MMC
> core can pick the best mode supported by the card.
>
> Tested: Realtek RTS5129 (0bda:0129) + tray + Lexar 2TB SDXC
> Tested: timing spec SDR104 @ 208 MHz, signal voltage 1.8 V (2026-02-24)
> Signed-off-by: Sean Rhodes <sean@starlabs.systems>
> ---
>  drivers/mmc/host/rtsx_usb_sdmmc.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c
> index 6be98926387d..8d5ebe92018e 100644
> --- a/drivers/mmc/host/rtsx_usb_sdmmc.c
> +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c
> @@ -1487,6 +1487,7 @@ static void rtsx_usb_init_host(struct rtsx_usb_sdmmc *host)
>         mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SD_HIGHSPEED |
>                 MMC_CAP_MMC_HIGHSPEED | MMC_CAP_BUS_WIDTH_TEST |
>                 MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | MMC_CAP_UHS_SDR50 |
> +               MMC_CAP_UHS_DDR50 | MMC_CAP_UHS_SDR104 |

Please drop this patch from the series for now.

My point is that the series addresses enough of complicated problems,
so I suggest we start by fixing them first before adding new
functionality.

>                 MMC_CAP_SYNC_RUNTIME_PM;
>         mmc->caps2 = MMC_CAP2_NO_PRESCAN_POWERUP | MMC_CAP2_FULL_PWR_CYCLE |
>                 MMC_CAP2_NO_SDIO;
> --
> 2.51.0

Kind regards
Uffe