> On Thu, 22 Aug 2024 at 15:17, Avri Altman <Avri.Altman@xxxxxxx> wrote:
> >
> > > On Wed, 14 Aug 2024 at 09:31, Avri Altman <avri.altman@xxxxxxx>
> wrote:
> > > >
> > > > ACMD41 was extended to support the host-card handshake during
> > > > initialization. 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 ACMD41
> > > > until eventually, the host will timed out and give up.
> > > >
> > > > Tested-by: Ricky WU <ricky_wu@xxxxxxxxxxx>
> > > > 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;
> > > > +
> > >
> > > This code doesn't belong in mmc_send_app_op_cond(), but rather in
> > > mmc_sd_get_cid(), which is where we add one various OCR bits before
> > > we call
> > > mmc_send_app_op_cond() with it.
> > >
> > > For example, if the response of the SD_SEND_IF_COND commands
> > > indicates an SD 2.0 compliant card, we tag on the SD_OCR_CCS bit. It
> > > looks like that needs to be extended to the SD_OCR_2T bit too.
> > OK.
> >
> > >
> > > > 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;
> > >
> > > Please don't abuse the host->caps2 for this purpose.
> > >
> > > Instead let's keep using the card->state to keep track of what type
> > > of card this is. You may have a look at how the MMC_CARD_SDXC bit is
> > > being used and just follow that behaviour for the SDUC cards too.
> > >
> > > Moreover, rather than assigning card->state at this point, let's do
> > > that from
> > > mmc_decode_csd() instead, when we realize that the card supports the
> > > new CSD structure version 3.
> > Just to recap - so we are all on the same page:
> > Ricky suggested this in v1 as well.
> > And we had a discussion if we should use the state field to indicate the card
> type.
> > However, Ricky had some good point why it should be here:
> > "...
> > 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 ..."
> > This is because according to the spec, SDUC identification is not mandated by
> its capacity, but rather by the rocr.
>
> In principle you are right. The rocr indicates whether it's an SDSC, SDHC, SDXC
> or an SDUC card.
>
> On the other hand we are checking the CSD structure version for
> SDSC/SDHC/SDXC - so I would rather be consistent with that way, as it seems
> to work fine.
Yes.
>
> According to the spec the CSD structure version 3 is dedicated for SDUC cards,
> right?
Yes.
Thanks,
Avri
>
> [...]
>
> Kind regards
> Uffe
