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Date: Tue, 18 Jun 2024 18:47:36 +0800
From: Victor Shih <victorshihgli@...il.com>
To: Adrian Hunter <adrian.hunter@...el.com>
Cc: linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
benchuanggli@...il.com, HL.Liu@...esyslogic.com.tw,
Greg.tu@...esyslogic.com.tw, takahiro.akashi@...aro.org, dlunev@...omium.org,
Ben Chuang <ben.chuang@...esyslogic.com.tw>,
Victor Shih <victor.shih@...esyslogic.com.tw>, ulf.hansson@...aro.org
Subject: Re: [PATCH V16 08/23] mmc: core: Support UHS-II Auto Command Error Recovery
On Mon, Jun 17, 2024 at 1:04 PM Adrian Hunter <adrian.hunter@...el.com> wrote:
>
> On 9/06/24 21:40, Victor Shih wrote:
> > On Fri, May 31, 2024 at 7:23 PM Adrian Hunter <adrian.hunter@...el.com> wrote:
> >>
> >> On 31/05/24 13:31, Victor Shih wrote:
> >>> On Fri, May 24, 2024 at 2:54 PM Adrian Hunter <adrian.hunter@...el.com> wrote:
> >>>>
> >>>> On 22/05/24 14:08, Victor Shih wrote:
> >>>>> From: Victor Shih <victor.shih@...esyslogic.com.tw>
> >>>>>
> >>>>> Add UHS-II Auto Command Error Recovery functionality
> >>>>> into the MMC request processing flow.
> >>>>
> >>>> Not sure what "auto" means here, but the commit message
> >>>> should outline what the spec. requires for error recovery.
> >>>>
> >>>
> >>> Hi, Adrian
> >>>
> >>> I will add instructions in the v17 version.
> >>>
> >>> Thanks, Victor Shih
> >>>
> >>>>>
> >>>>> Signed-off-by: Ben Chuang <ben.chuang@...esyslogic.com.tw>
> >>>>> Signed-off-by: Victor Shih <victor.shih@...esyslogic.com.tw>
> >>>>> ---
> >>>>>
> >>>>> Updates in V16:
> >>>>> - Separate the Error Recovery mechanism from patch#7 to patch#8.
> >>>>>
> >>>>> ---
> >>>>>
> >>>>> drivers/mmc/core/core.c | 4 ++
> >>>>> drivers/mmc/core/core.h | 1 +
> >>>>> drivers/mmc/core/sd_uhs2.c | 80 ++++++++++++++++++++++++++++++++++++++
> >>>>> include/linux/mmc/host.h | 6 +++
> >>>>> 4 files changed, 91 insertions(+)
> >>>>>
> >>>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> >>>>> index 68496c51a521..18642afc405f 100644
> >>>>> --- a/drivers/mmc/core/core.c
> >>>>> +++ b/drivers/mmc/core/core.c
> >>>>> @@ -403,6 +403,10 @@ void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq)
> >>>>> while (1) {
> >>>>> wait_for_completion(&mrq->completion);
> >>>>>
> >>>>> + if (host->ops->get_cd(host))
> >>>>> + if (mrq->cmd->error || (mrq->data && mrq->data->error))
> >>>>> + mmc_sd_uhs2_error_recovery(host, mrq);
> >>>>
> >>>> There are several issues with this:
> >>>>
> >>>> 1. It is not OK to start a request from within the request path
> >>>> because it is recursive:
> >>>>
> >>>> mmc_wait_for_req_done() <--
> >>>> mmc_sd_uhs2_error_recovery()
> >>>> sd_uhs2_abort_trans()
> >>>> mmc_wait_for_cmd()
> >>>> mmc_wait_for_req()
> >>>> mmc_wait_for_req_done() <--
> >>>>
> >>>> 2. The mmc block driver does not use this path
> >>>>
> >>>> 3. No need to always call ->get_cd() if there is no error
> >>>>
> >>>> It is worth considering whether the host controller could
> >>>> send the abort command as part of the original request, as
> >>>> is done with the stop command.
> >>>>
> >>>
> >>> Hi, Adrian
> >>>
> >>> 1. It looks like just issuing a command in
> >>> mmc_wait_for_req_done() will cause a recursion.
> >>> I will drop sd_uhs2_abort_trans() and
> >>> sd_uhs2_abort_status_read() in the v17 version.
> >>> 2. I have no idea about this part, could you please give me some advice?
> >>
> >> The mmc block driver sets the ->done() callback and so
> >> mmc_wait_for_req_done() is never called for data transfers.
> >>
> >> That won't matter if the host controller handles doing
> >> the abort command, as was suggested elsewhere.
> >>
> >>> 3. I will try to modify this part in the v17 version.
> >>>
> >>> Thanks, Victor Shih
> >>>
> >>>>> +
> >>>>> cmd = mrq->cmd;
> >>>>>
> >>>>> if (!cmd->error || !cmd->retries ||
> >>>>> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
> >>>>> index 920323faa834..259d47c8bb19 100644
> >>>>> --- a/drivers/mmc/core/core.h
> >>>>> +++ b/drivers/mmc/core/core.h
> >>>>> @@ -82,6 +82,7 @@ int mmc_attach_mmc(struct mmc_host *host);
> >>>>> int mmc_attach_sd(struct mmc_host *host);
> >>>>> int mmc_attach_sdio(struct mmc_host *host);
> >>>>> int mmc_attach_sd_uhs2(struct mmc_host *host);
> >>>>> +void mmc_sd_uhs2_error_recovery(struct mmc_host *mmc, struct mmc_request *mrq);
> >>>>>
> >>>>> /* Module parameters */
> >>>>> extern bool use_spi_crc;
> >>>>> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> >>>>> index 85939a2582dc..d5acb4e6ccac 100644
> >>>>> --- a/drivers/mmc/core/sd_uhs2.c
> >>>>> +++ b/drivers/mmc/core/sd_uhs2.c
> >>>>> @@ -1324,3 +1324,83 @@ int mmc_attach_sd_uhs2(struct mmc_host *host)
> >>>>>
> >>>>> return err;
> >>>>> }
> >>>>> +
> >>>>> +static void sd_uhs2_abort_trans(struct mmc_host *mmc)
> >>>>> +{
> >>>>> + struct mmc_request mrq = {};
> >>>>> + struct mmc_command cmd = {0};
> >>>>> + struct uhs2_command uhs2_cmd = {};
> >>>>> + int err;
> >>>>> +
> >>>>> + mrq.cmd = &cmd;
> >>>>> + mmc->ongoing_mrq = &mrq;
> >>>>> +
> >>>>> + uhs2_cmd.header = UHS2_NATIVE_PACKET | UHS2_PACKET_TYPE_CCMD |
> >>>>> + mmc->card->uhs2_config.node_id;
> >>>>> + uhs2_cmd.arg = ((UHS2_DEV_CMD_TRANS_ABORT & 0xFF) << 8) |
> >>>>> + UHS2_NATIVE_CMD_WRITE |
> >>>>> + (UHS2_DEV_CMD_TRANS_ABORT >> 8);
> >>>>> +
> >>>>> + sd_uhs2_cmd_assemble(&cmd, &uhs2_cmd, 0, 0);
> >>>>> + err = mmc_wait_for_cmd(mmc, &cmd, 0);
> >>>>> +
> >>>>> + if (err)
> >>>>> + pr_err("%s: %s: UHS2 CMD send fail, err= 0x%x!\n",
> >>>>> + mmc_hostname(mmc), __func__, err);
> >>>>> +}
> >>>>> +
> >>>>> +static void sd_uhs2_abort_status_read(struct mmc_host *mmc)
> >>>>> +{
> >>>>> + struct mmc_request mrq = {};
> >>>>> + struct mmc_command cmd = {0};
> >>>>> + struct uhs2_command uhs2_cmd = {};
> >>>>> + int err;
> >>>>> +
> >>>>> + mrq.cmd = &cmd;
> >>>>> + mmc->ongoing_mrq = &mrq;
> >>>>> +
> >>>>> + uhs2_cmd.header = UHS2_NATIVE_PACKET |
> >>>>> + UHS2_PACKET_TYPE_CCMD |
> >>>>> + mmc->card->uhs2_config.node_id;
> >>>>> + uhs2_cmd.arg = ((UHS2_DEV_STATUS_REG & 0xFF) << 8) |
> >>>>> + UHS2_NATIVE_CMD_READ |
> >>>>> + UHS2_NATIVE_CMD_PLEN_4B |
> >>>>> + (UHS2_DEV_STATUS_REG >> 8);
> >>>>> +
> >>>>> + sd_uhs2_cmd_assemble(&cmd, &uhs2_cmd, 0, 0);
> >>>>> + err = mmc_wait_for_cmd(mmc, &cmd, 0);
> >>>>> +
> >>>>> + if (err)
> >>>>> + pr_err("%s: %s: UHS2 CMD send fail, err= 0x%x!\n",
> >>>>> + mmc_hostname(mmc), __func__, err);
> >>>>> +}
> >>>>> +
> >>>>> +void mmc_sd_uhs2_error_recovery(struct mmc_host *mmc, struct mmc_request *mrq)
> >>>>> +{
> >>>>> + mmc->ops->uhs2_reset_cmd_data(mmc);
> >>>>
> >>>> The host controller should already have done any resets needed.
> >>>> sdhci already has support for doing that - see host->pending_reset
> >>>>
> >>>
> >>> Hi, Adrian
> >>>
> >>> I'm not sure what this means. Could you please give me more information?
> >>
> >> sdhci_uhs2_request_done() checks sdhci_needs_reset() and does
> >> sdhci_uhs2_reset().
> >>
> >> sdhci_needs_reset() does not cater for data errors because
> >> the reset for data errors is done directly in what becomes
> >> __sdhci_finish_data_common().
> >>
> >> You may need to:
> >> 1. add a parameter to __sdhci_finish_data_common() to
> >> skip doing the sdhci reset and instead set
> >> host->pending_reset
> >> 2. amend sdhci_uhs2_request_done() to check for data error
> >> also to decide if a reset is needed
> >>
> >
> > Hi, Adrian
> >
> > If there is any mistake in my understanding, please help me correct it.
> > My understanding is as follows:
> >
> > static bool sdhci_uhs2_request_done(struct sdhci_host *host)
> > {
> > ...
> > if (sdhci_needs_reset(host, mrq)) {
> > ...
> > if (mrq->cmd->error || (mrq->data && mrq->data->error))
> > sdhci_uhs2_reset_cmd_data(host->mmc);
> > ...
> > }
> > ...
> > }
>
> Like this:
>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 47180429448b..3cb5fe1d488c 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -581,7 +581,7 @@ static void sdhci_uhs2_finish_data(struct sdhci_host *host)
> {
> struct mmc_data *data = host->data;
>
> - __sdhci_finish_data_common(host);
> + __sdhci_finish_data_common(host, true);
>
> __sdhci_finish_mrq(host, data->mrq);
> }
> @@ -932,6 +932,12 @@ static void sdhci_uhs2_request(struct mmc_host *mmc, struct mmc_request *mrq)
> * *
> \*****************************************************************************/
>
> +static bool sdhci_uhs2_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
> +{
> + return sdhci_needs_reset(host, mrq) ||
> + (!(host->flags & SDHCI_DEVICE_DEAD) && mrq->data && mrq->data->error);
> +}
> +
> static bool sdhci_uhs2_request_done(struct sdhci_host *host)
> {
> unsigned long flags;
> @@ -963,7 +969,7 @@ static bool sdhci_uhs2_request_done(struct sdhci_host *host)
> * The controller needs a reset of internal state machines
> * upon error conditions.
> */
> - if (sdhci_needs_reset(host, mrq)) {
> + if (sdhci_uhs2_needs_reset(host, mrq)) {
> /*
> * Do not finish until command and data lines are available for
> * reset. Note there can only be one other mrq, so it cannot
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index ed55aab24f92..55f0db0fc007 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1563,7 +1563,7 @@ void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
> }
> EXPORT_SYMBOL_GPL(sdhci_finish_mrq);
>
> -void __sdhci_finish_data_common(struct sdhci_host *host)
> +void __sdhci_finish_data_common(struct sdhci_host *host, bool defer_reset)
> {
> struct mmc_command *data_cmd = host->data_cmd;
> struct mmc_data *data = host->data;
> @@ -1576,7 +1576,9 @@ void __sdhci_finish_data_common(struct sdhci_host *host)
> * conditions.
> */
> if (data->error) {
> - if (!host->cmd || host->cmd == data_cmd)
> + if (defer_reset)
> + host->pending_reset = true;
> + else if (!host->cmd || host->cmd == data_cmd)
> sdhci_reset_for(host, REQUEST_ERROR);
> else
> sdhci_reset_for(host, REQUEST_ERROR_DATA_ONLY);
> @@ -1604,7 +1606,7 @@ static void __sdhci_finish_data(struct sdhci_host *host, bool sw_data_timeout)
> {
> struct mmc_data *data = host->data;
>
> - __sdhci_finish_data_common(host);
> + __sdhci_finish_data_common(host, false);
>
> /*
> * Need to send CMD12 if -
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 576b8de2c04e..5ac5234fecf0 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -840,7 +840,7 @@ void sdhci_prepare_dma(struct sdhci_host *host, struct mmc_data *data);
> bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq);
> void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq);
> void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq);
> -void __sdhci_finish_data_common(struct sdhci_host *host);
> +void __sdhci_finish_data_common(struct sdhci_host *host, bool defer_reset);
> bool sdhci_present_error(struct sdhci_host *host, struct mmc_command *cmd, bool present);
> u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
> unsigned int *actual_clock);
>
>
Hi, Adrian
Please let me confirm with you. Based on your above comments, will the
sdhci_uhs2_request_done()
be modified to option 1 or option 2?
After testing, when a command error occurs, only executing
sdhci_uhs2_reset() has no effect,
we need to execute the reset DAT Line and CMD Line. So option 3 has no effect.
option 1:
static bool sdhci_uhs2_request_done(struct sdhci_host *host)
{
...
if (sdhci_uhs2_needs_reset(host, mrq)) {
...
if (host->pending_reset)
sdhci_uhs2_reset_cmd_data(host->mmc);
else
sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET);
host->pending_reset = false;
}
...
}
option 2:
static bool sdhci_uhs2_request_done(struct sdhci_host *host)
{
...
if (sdhci_uhs2_needs_reset(host, mrq)) {
...
sdhci_uhs2_reset_cmd_data(host->mmc);
host->pending_reset = false;
}
...
}
option 3:
static bool sdhci_uhs2_request_done(struct sdhci_host *host)
{
...
if (sdhci_uhs2_needs_reset(host, mrq)) {
...
sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET);
host->pending_reset = false;
}
...
}
Thanks, Victor Shih
> >
> > I have another question. the sdhci_uhs2_request_done() belongs to the patch#18.
> > Can the above content be modified directly in the patch#18?
> > Or does it need to be separated into another patch?
>
> Please update the existing patches.
>
> >
> > Thanks, Victor Shih
> >
> >>>
> >>> Thanks, Victor Shih
> >>>
> >>>>> +
> >>>>> + if (mrq->data) {
> >>>>> + if (mrq->data->error && mmc_card_uhs2(mmc)) {
> >>>>> + if (mrq->cmd) {
> >>>>> + switch (mrq->cmd->error) {
> >>>>> + case ETIMEDOUT:
> >>>>> + case EILSEQ:
> >>>>> + case EIO:
> >>>>> + sd_uhs2_abort_trans(mmc);
> >>>>> + sd_uhs2_abort_status_read(mmc);
> >>>>
> >>>> What is the purpose of sd_uhs2_abort_status_read() here?
> >>>> It is not obvious it does anything.
> >>>>
> >>>
> >>> Hi, Adrian
> >>>
> >>> sd_uhs2_abort_status_read() seems to only have read status,
> >>> I will drop this in the v17 version.
> >>>
> >>> Thanks, Victor Shih
> >>>
> >>>>> + break;
> >>>>> + default:
> >>>>> + break;
> >>>>> + }
> >>>>> + }
> >>>>> + }
> >>>>> + } else {
> >>>>> + if (mrq->cmd) {
> >>>>> + switch (mrq->cmd->error) {
> >>>>> + case ETIMEDOUT:
> >>>>> + sd_uhs2_abort_trans(mmc);
> >>>>> + break;
> >>>>> + }
> >>>>> + }
> >>>>> + }
> >>>>> +}
> >>>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> >>>>> index fc9520b3bfa4..c914a58f7e1e 100644
> >>>>> --- a/include/linux/mmc/host.h
> >>>>> +++ b/include/linux/mmc/host.h
> >>>>> @@ -271,6 +271,12 @@ struct mmc_host_ops {
> >>>>> * negative errno in case of a failure or zero for success.
> >>>>> */
> >>>>> int (*uhs2_control)(struct mmc_host *host, enum sd_uhs2_operation op);
> >>>>> +
> >>>>> + /*
> >>>>> + * The uhs2_reset_cmd_data callback is used to excute reset
> >>>>> + * when a auto command error occurs.
> >>>>> + */
> >>>>> + void (*uhs2_reset_cmd_data)(struct mmc_host *host);
> >>>>> };
> >>>>>
> >>>>> struct mmc_cqe_ops {
> >>>>
> >>
>
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