Re: [PATCH V4 07/11] mmc: mmc: Enable CQE's

Adrian Hunter
2017-08-10T09:57:08Z

On 07/08/17 17:51, Ulf Hansson wrote:
> On 21 July 2017 at 11:49, Adrian Hunter <adrian.hunter@intel.com> wrote:
>> Enable or disable CQE when a card is added or removed respectively.
>
> As a standalone change, this is hard to understand.
>
> Perhaps if you squash this with some the patche calling ->cqe_off()
> and the one actually setting ext_csd.cmdq_en, I can get a better
> picture.

No they are not related.

>
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>> drivers/mmc/core/bus.c | 7 +++++++
>> drivers/mmc/core/mmc.c | 13 +++++++++++++
>> 2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
>> index 301246513a37..a4b49e25fe96 100644
>> --- a/drivers/mmc/core/bus.c
>> +++ b/drivers/mmc/core/bus.c
>> @@ -369,10 +369,17 @@ int mmc_add_card(struct mmc_card *card)
>> */
>> void mmc_remove_card(struct mmc_card *card)
>> {
>> + struct mmc_host *host = card->host;
>> +
>> #ifdef CONFIG_DEBUG_FS
>> mmc_remove_card_debugfs(card);
>> #endif
>>
>> + if (host->cqe_enabled) {
>> + host->cqe_ops->cqe_disable(host);
>> + host->cqe_enabled = false;
>> + }
>> +
>
> This doesn't feel like the correct place to disable cqe.
>
> Primarily because I don't think you enable cqe in mmc_add_card(), so
> this isn't consistent.

mmc_add_card() and mmc_remove_card() are not paired functions. Instead
mmc_remove_card() is on the error path of the ..._init_card() functions and
consequently this is the best place for cqe->disable().

>
>> if (mmc_card_present(card)) {
>> if (mmc_host_is_spi(card->host)) {
>> pr_info("%s: SPI card removed\n",
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index 2ff0caf92bc8..92c6167d64e0 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -1804,6 +1804,19 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>> */
>> card->reenable_cmdq = card->ext_csd.cmdq_en;
>>
>> + if (card->ext_csd.cmdq_en && (host->caps2 & MMC_CAP2_CQE) &&
>> + !host->cqe_enabled) {
>
> I assume card->ext_csd.cmdq_en can't be set, unless the MMC_CAP2_CQE
> bit also is set. So there should be no reason to check it here again?

Yes, it is a left-over from software command queue support. I will remove it.

>
> Also, can ever host->cqe_enabled be true in this path? If so, isn't
> that wrong by itself?

No, it can be set on the reset path.

>
>> + err = host->cqe_ops->cqe_enable(host, card);
>> + if (err) {
>> + pr_err("%s: Failed to enable CQE, error %d\n",
>> + mmc_hostname(host), err);
>> + } else {
>> + host->cqe_enabled = true;
>> + pr_info("%s: Command Queue Engine enabled\n",
>> + mmc_hostname(host));
>> + }
>> + }
>> +
>> /*
>> * The mandatory minimum values are defined for packed command.
>> * read: 5, write: 3
>> --
>> 1.9.1
>>
>
> Kind regards
> Uffe
>