> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Sent: Monday, August 15, 2022 4:33 PM
> To: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> Cc: linux-mmc <linux-mmc@xxxxxxxxxxxxxxx>; Seunghui Lee
> <sh043.lee@xxxxxxxxxxx>; DooHyun Hwang <dh0421.hwang@xxxxxxxxxxx>
> Subject: [PATCH 2/2] mmc: sd: Fix inconsistent sd3_bus_mode with failed
> voltage switch
>
> If re-initialization results is a different signal voltage, because the
> voltage switch failed previously but not this time (or vice versa), then
> sd3_bus_mode will be inconsistent with the card because the SD_SWITCH
> command is done only upon first initialization.
>
> Fix by always reading SD_SWITCH information during re-initialization which
> also means it does not need to be re-read later for the 1.8V fixup
> workaround.
>
> Note, brief testing showed SD_SWITCH took about 1.8ms to 2ms which added
> about 1% to 1.5% to the re-initialization time, so not particularly
> significant.
>
> Reported-by: Seunghui Lee <sh043.lee@xxxxxxxxxxx>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/core/sd.c | 42 ++++++++++++++++--------------------------
> 1 file changed, 16 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
> bc84d7dfc8e1..06aa62ce0ed1 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -949,15 +949,16 @@ int mmc_sd_setup_card(struct mmc_host *host, struct
> mmc_card *card,
>
> /* Erase init depends on CSD and SSR */
> mmc_init_erase(card);
> -
> - /*
> - * Fetch switch information from card.
> - */
> - err = mmc_read_switch(card);
> - if (err)
> - return err;
> }
>
> + /*
> + * Fetch switch information from card. Note, sd3_bus_mode can
> change if
> + * voltage switch outcome changes, so do this always.
> + */
> + err = mmc_read_switch(card);
> + if (err)
> + return err;
> +
> /*
> * For SPI, enable CRC as appropriate.
> * This CRC enable is located AFTER the reading of the @@ -1480,26
> +1481,15 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
> if (!v18_fixup_failed && !mmc_host_is_spi(host) &&
> mmc_host_uhs(host) &&
> mmc_sd_card_using_v18(card) &&
> host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
> - /*
> - * Re-read switch information in case it has changed since
> - * oldcard was initialized.
> - */
> - if (oldcard) {
> - err = mmc_read_switch(card);
> - if (err)
> - goto free_card;
> - }
> - if (mmc_sd_card_using_v18(card)) {
> - if (mmc_host_set_uhs_voltage(host) ||
> - mmc_sd_init_uhs_card(card)) {
> - v18_fixup_failed = true;
> - mmc_power_cycle(host, ocr);
> - if (!oldcard)
> - mmc_remove_card(card);
> - goto retry;
> - }
> - goto cont;
> + if (mmc_host_set_uhs_voltage(host) ||
> + mmc_sd_init_uhs_card(card)) {
> + v18_fixup_failed = true;
> + mmc_power_cycle(host, ocr);
> + if (!oldcard)
> + mmc_remove_card(card);
> + goto retry;
> }
> + goto cont;
> }
>
> /* Initialization sequence for UHS-I cards */
> --
> 2.25.1
I've just tested this.
It works well.
Thank you for your work.
Reviewed-by: Seunghui Lee <sh043.lee@xxxxxxxxxxx>
