Hi,
Thanks for having a look.
> Hi Avri,
>
> 在 2024/8/14 15:29, Avri Altman 写道:
> > @@ -948,13 +949,20 @@ static int mmc_sd_num_wr_blocks(struct mmc_card
> *card, u32 *written_blocks)
> > int err;
> > u32 result;
> > __be32 *blocks;
> > -
> > + u8 resp_sz;
> > struct mmc_request mrq = {};
> > struct mmc_command cmd = {};
> > struct mmc_data data = {};
> > -
> > struct scatterlist sg;
> >
> > + /*
> > + * SD cards, specifically high volume cards, expect to be allowed with the
> > + * full 500msec busy period post write. Otherwise, they may not indicate
> > + * correctly the number of bytes written.
> > + */
> > + if (mmc_card_is_sduc(card->host))
> > + mmc_delay(500);
>
> Could you kindly point me to the right section of SD spec which states
> this 500ms before ACMD22 ? Is it the write busy time?
Yes. I encountered it while testing SDUC:
If there are some phy errors (probably caused because the micro-to-SD adapter I was using),
The first get-status response contains an error bit, and the recovery flow is entered immediately.
Thus, violating the min 500msec allotted to the card write.
>
> And as you mentioned high volume cards, I am curious if 1TB sandisk
> MircoSDXC need 500ms delay as well?
Theoretically should be applied to all cards.
But since this code is there since forever, and no issue observed thus far -
I preferred limiting this to ultra capacity cards only.
Thanks,
Avri
