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From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
To:     arnd@arndb.de, gregkh@linuxfoundation.org
Cc:     ulf.hansson@linaro.org, stern@rowland.harvard.edu,
        bauer.chen@realtek.com, ricky_wu@realtek.com,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        Kai-Heng Feng <kai.heng.feng@canonical.com>
Subject: [PATCH 1/5] misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection
Date:   Mon, 23 Jul 2018 18:27:40 +0800
Message-Id: <20180723102744.15140-2-kai.heng.feng@canonical.com>
In-Reply-To: <20180723102744.15140-1-kai.heng.feng@canonical.com>
References: <20180723102744.15140-1-kai.heng.feng@canonical.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Although rtsx_usb doesn't support card removal detection, card insertion
will resume rtsx_usb by USB remote wakeup signaling.

When rtsx_usb gets resumed, also resumes its child devices,
rtsx_usb_sdmmc and rtsx_usb_ms, to notify them there's a card in its
slot.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/misc/cardreader/rtsx_usb.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c
index b97903ff1a72..fed83453e5c5 100644
--- a/drivers/misc/cardreader/rtsx_usb.c
+++ b/drivers/misc/cardreader/rtsx_usb.c
@@ -723,8 +723,20 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
 	return 0;
 }
 
+static int rtsx_usb_resume_child(struct device *dev, void *data)
+{
+	/* No need to wake up self again */
+	if (dev == data)
+		return 0;
+
+	dev_dbg(dev, "%s called\n", __func__);
+	pm_request_resume(dev);
+	return 0;
+}
+
 static int rtsx_usb_resume(struct usb_interface *intf)
 {
+	device_for_each_child(&intf->dev, &intf->dev, rtsx_usb_resume_child);
 	return 0;
 }
 
@@ -734,6 +746,7 @@ static int rtsx_usb_reset_resume(struct usb_interface *intf)
 		(struct rtsx_ucr *)usb_get_intfdata(intf);
 
 	rtsx_usb_reset_chip(ucr);
+	device_for_each_child(&intf->dev, &intf->dev, rtsx_usb_resume_child);
 	return 0;
 }
 
-- 
2.17.1