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mfd: rtsx_usb: Defer autosuspend while card exists

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A card insertion happens after the lastest polling before reader is
suspended may never have a chance to be detected. Under current 1-HZ
polling interval setting in mmc_core, the worst case of such
undetectablility is about 1 second.

To further reduce the undetectability, detect card slot again in suspend
method and defer the autosuspend if the slot is loaded. The default 2
second autosuspend delay of USB subsystem should let the next polling
detects the card.

Signed-off-by: Roger Tseng <rogerable@realtek.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Roger Tseng 2015-01-21 18:09:21 +08:00 committed by Lee Jones
parent c7f15d43a5
commit bb400d2120
1 changed files with 18 additions and 0 deletions
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18
drivers/mfd/rtsx_usb.c
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@ -681,9 +681,27 @@ static void rtsx_usb_disconnect(struct usb_interface *intf)
#ifdef CONFIG_PM
static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
{
struct rtsx_ucr *ucr =
(struct rtsx_ucr *)usb_get_intfdata(intf);
u16 val = 0;
dev_dbg(&intf->dev, "%s called with pm message 0x%04x\n",
__func__, message.event);
if (PMSG_IS_AUTO(message)) {
if (mutex_trylock(&ucr->dev_mutex)) {
rtsx_usb_get_card_status(ucr, &val);
mutex_unlock(&ucr->dev_mutex);
/* Defer the autosuspend if card exists */
if (val & (SD_CD | MS_CD))
return -EAGAIN;
} else {
/* There is an ongoing operation*/
return -EAGAIN;
}
}
return 0;
}