diff mbox series

[v2] mmc: block: ioctl: No busywaiting of non-TRAN CMDs

Message ID CWXP265MB2680A8DD0FFA6FECBFDFB027C4579@CWXP265MB2680.GBRP265.PROD.OUTLOOK.COM
State New
Headers show
Series [v2] mmc: block: ioctl: No busywaiting of non-TRAN CMDs | expand

Commit Message

Christian Loehle May 7, 2021, 10:34 a.m. UTC
Prevent busywaiting for TRAN state indication
after issuing a command that will not transition
to TRAN state.

Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
---
 drivers/mmc/core/block.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Comments

Ulf Hansson May 7, 2021, 11:34 a.m. UTC | #1
On Fri, 7 May 2021 at 12:34, Christian Löhle <CLoehle@hyperstone.com> wrote:
>
> Prevent busywaiting for TRAN state indication
> after issuing a command that will not transition
> to TRAN state.
>
> Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
> ---
>  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
Christian Loehle May 11, 2021, 4:07 p.m. UTC | #2
On Friday, May 7, 2021 1:34 PM,Ulf Hansson <ulf.hansson@linaro.org> wrote:
>

> 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.


You are absolutely correct, my bad, I had a userspace program setting the
flags wrong.
Even for a SEND_STATUS R1B is only expected if the card was not selected
and should be set accordingly by the userspace.

Regards,
Christian
Hyperstone GmbH | Line-Eid-Strasse 3 | 78467 Konstanz
Managing Directors: Dr. Jan Peter Berns.
Commercial register of local courts: Freiburg HRB381782
diff mbox series

Patch

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)) {
 		/*
 		 * Ensure RPMB/R1B command has completed by polling CMD13
 		 * "Send Status".