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Message-ID: <1e7d20d9-619e-4c82-802b-6e99a1a71a95@intel.com>
Date: Tue, 18 Jun 2024 14:13:06 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: Victor Shih <victorshihgli@...il.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 18/06/24 13:47, Victor Shih wrote:
> 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.
Obviously do whatever reset is necessary. Don't use
pending_reset to differentiate which reset, because it
doesn't mean anything other than what it says. Instead
look at the mrq->data, mrq->data->error etc
>
> 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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