Commit bb400d21 authored Jan 21, 2015 by Roger Tseng Committed by Lee Jones Jan 22, 2015

mfd: rtsx_usb: Defer autosuspend while card exists



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>

parent c7f15d43

drivers/mfd/rtsx_usb.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}