>
> ACMD21 was extended to support the host-card handshake during initialization.
Is ACMD41?
> The card expects that the HCS & HO2T bits to be set in the command
> argument, and sets the applicable bits in the R3 returned response. On the
> contrary, if a SDUC card is inserted to a non-supporting host, it will never
> respond to this ACMD21 until eventually, the host will timed out and give up.
>
> Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
> ---
> drivers/mmc/core/sd_ops.c | 19 +++++++++++++++----
> include/linux/mmc/host.h | 6 ++++++
> include/linux/mmc/sd.h | 1 +
> 3 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c index
> 8b9b34286ef3..7f6963dac873 100644
> --- a/drivers/mmc/core/sd_ops.c
> +++ b/drivers/mmc/core/sd_ops.c
> @@ -168,12 +168,16 @@ int mmc_send_app_op_cond(struct mmc_host *host,
> u32 ocr, u32 *rocr)
> .cmd = &cmd
> };
> int err;
> + u32 sduc_arg = SD_OCR_CCS | SD_OCR_2T;
>
> cmd.opcode = SD_APP_OP_COND;
> + cmd.arg = ocr;
> +
> if (mmc_host_is_spi(host))
> - cmd.arg = ocr & (1 << 30); /* SPI only defines one bit */
> + cmd.arg &= (1 << 30); /* SPI only defines one bit */
> else
> - cmd.arg = ocr;
> + cmd.arg |= sduc_arg;
> +
> cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
>
> err = __mmc_poll_for_busy(host, SD_APP_OP_COND_PERIOD_US,
> @@ -182,8 +186,15 @@ int mmc_send_app_op_cond(struct mmc_host *host,
> u32 ocr, u32 *rocr)
> if (err)
> return err;
>
> - if (rocr && !mmc_host_is_spi(host))
> - *rocr = cmd.resp[0];
> + if (!mmc_host_is_spi(host)) {
> + if (rocr)
> + *rocr = cmd.resp[0];
> +
> + if ((cmd.resp[0] & sduc_arg) == sduc_arg)
> + host->caps2 |= MMC_CAP2_SD_SDUC;
> + else
> + host->caps2 &= ~MMC_CAP2_SD_SDUC;
I think host->caps2 is for host to claim caps, here can just call mmc_card_set_ult_capacity?
Don't need to wait csd, because SDXC and SDHC need to identify by capacity, but SDUC can be identified here
And all your mmc_card_is_sduc() I think change to mmc_card_ult_capacity() to know the card type
> + }
>
> return 0;
> }
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index
> 88c6a76042ee..a9c36a3e1a10 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -427,6 +427,7 @@ struct mmc_host {
> #define MMC_CAP2_CRYPTO 0
> #endif
> #define MMC_CAP2_ALT_GPT_TEGRA (1 << 28) /* Host with eMMC
> that has GPT entry at a non-standard location */
> +#define MMC_CAP2_SD_SDUC (1 << 29) /* SD over 2TB */
>
> int fixed_drv_type; /* fixed driver type for
> non-removable media */
>
> @@ -638,6 +639,11 @@ static inline int mmc_card_uhs(struct mmc_card
> *card)
> card->host->ios.timing <= MMC_TIMING_UHS_DDR50; }
>
> +static inline int mmc_card_is_sduc(struct mmc_host *host) {
> + return host->caps2 & MMC_CAP2_SD_SDUC; }
> +
> void mmc_retune_timer_stop(struct mmc_host *host);
>
> static inline void mmc_retune_needed(struct mmc_host *host) diff --git
> a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h index
> 6727576a8755..865cc0ca8543 100644
> --- a/include/linux/mmc/sd.h
> +++ b/include/linux/mmc/sd.h
> @@ -36,6 +36,7 @@
> /* OCR bit definitions */
> #define SD_OCR_S18R (1 << 24) /* 1.8V switching request
> */
> #define SD_ROCR_S18A SD_OCR_S18R /* 1.8V switching
> accepted by card */
> +#define SD_OCR_2T (1 << 27) /* HO2T/CO2T - SDUC
> support */
> #define SD_OCR_XPC (1 << 28) /* SDXC power control */
> #define SD_OCR_CCS (1 << 30) /* Card Capacity Status */
>
> --
> 2.25.1
