[...]
>> static int mmc_poweroff_notify(struct mmc_card *card, unsigned int notify_type)
>> {
>> - unsigned int timeout = card->ext_csd.generic_cmd6_time;
>> + unsigned int timeout;
>> + bool use_busy_signal = true;
>> int err;
>>
>> - /* Use EXT_CSD_POWER_OFF_SHORT as default notification type. */
>> - if (notify_type == EXT_CSD_POWER_OFF_LONG)
>> + switch (notify_type) {
>> + case EXT_CSD_POWER_OFF_LONG:
>> timeout = card->ext_csd.power_off_longtime;
>> + break;
>> + case EXT_CSD_SLEEP_NOTIFICATION:
>> + timeout = card->ext_csd.sleep_notification_time;
>> + use_busy_signal = false;
>
> This is wrong.
>
> If you set use_busy_signal to false, it means that we don't care about
> waiting for the card to stop signaling busy on DAT0 after setting
> EXT_CSD_SLEEP_NOTIFICATION. This then becomes a violation of the eMMC
> spec, because we must not issue a CMD5 before the card have stopped
> signaling busy.
>
> I realize that for those devices that don't support
> MMC_CAP_WAIT_WHILE_BUSY or have the ->card_busy() callback
> implemented, the consequence may be that mmc_poll_for_busy() may call
> mmc_delay() with a very big timeout. This could be a big problem, I
> guess.
Well, it may also be a big problem even if the host supports
->card_busy() and/or MMC_CAP_WAIT_WHILE_BUSY (but maybe not as big),
simply because we can't be waiting here for several seconds to allow
the card to deal with background operations.
I guess we need to try and see what happens. Perhaps you can share
some data about the timeouts you get?
>
>> + break;
>> + default:
>> + /* Use EXT_CSD_POWER_OFF_SHORT as default notification type. */
>> + timeout = card->ext_csd.generic_cmd6_time;
>> + }
>>
>> err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> EXT_CSD_POWER_OFF_NOTIFICATION,
>> - notify_type, timeout, 0, true, false, false);
>> + notify_type, timeout, 0, use_busy_signal, false, false);
>> if (err)
>> pr_err("%s: Power Off Notification timed out, %u\n",
>> mmc_hostname(card->host), timeout);
[...]
Kind regards
Uffe
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