On Fri, 7 May 2021 at 12:34, Christian Löhle <CLoehle@xxxxxxxxxxxxxx> wrote:
>
> Prevent busywaiting for TRAN state indication
> after issuing a command that will not transition
> to TRAN state.
>
> Signed-off-by: Christian Loehle <cloehle@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/core/block.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 689eb9afeeed..48be2ca5e3d1 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -446,6 +446,20 @@ static int card_busy_detect(struct mmc_card *card, unsigned int timeout_ms,
> return err;
> }
>
> +static inline bool is_tran_transition_cmd(struct mmc_command *cmd,
> + struct mmc_card *card)
> +{
> + /* Cards will not be in TRAN after completing identification commands
> + * or MMC_SEND_STATUS if they are not selected.
> + */
> + return !(cmd->opcode == MMC_SEND_CID
> + || cmd->opcode == MMC_ALL_SEND_CID
> + || cmd->opcode == MMC_SEND_CSD
> + || (cmd->opcode == MMC_SEND_STATUS &&
> + MMC_EXTRACT_INDEX_FROM_ARG(cmd->arg) != card->rca));
> +
> +}
> +
> static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
> struct mmc_blk_ioc_data *idata)
> {
> @@ -593,7 +607,8 @@ static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
>
> memcpy(&(idata->ic.response), cmd.resp, sizeof(cmd.resp));
>
> - if (idata->rpmb || (cmd.flags & MMC_RSP_R1B) == MMC_RSP_R1B) {
> + if ((idata->rpmb || (cmd.flags & MMC_RSP_R1B))
> + && is_tran_transition_cmd(&cmd, card)) {
None of the commands you are checking for should have an R1B response
according to the spec, I think.
That said, I don't think we should do these kinds of sanity checks in
the kernel for the mmc ioctls, that just doesn't scale.
> /*
> * Ensure RPMB/R1B command has completed by polling CMD13
> * "Send Status".
> --
Kind regards
Uffe
