linux-kernel - [PATCH v3 2/2] mfd: dln2: add suspend/resume functionality

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 19 Jan 2015 13:51:36 +0200
From:	Octavian Purdila <octavian.purdila@...el.com>
To:	lee.jones@...aro.org
Cc:	johan@...nel.org, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Octavian Purdila <octavian.purdila@...el.com>
Subject: [PATCH v3 2/2] mfd: dln2: add suspend/resume functionality

Without suspend/resume functionality in the USB driver the USB core
will disconnect and reconnect the DLN2 port and because the GPIO
framework does not yet support removal of an in-use controller a
suspend/resume operation will result in a crash.

This patch provides suspend and resume functions for the DLN2 driver
so that the above scenario is avoided, if the host controller does not
drop VBUS during suspend, since in this case the device state is
preserved.

We chose not implemented reset_resume so that if the host controller
does drop VBUS the resume path will go through above the
disconnect/reconnect process since it is probably better to fix the
GPIO framework disconnect issue then to save and restore the device
state for every driver.

Signed-off-by: Octavian Purdila <octavian.purdila@...el.com>
Reviewed-by: Johan Hovold <johan@...nel.org>
---
 drivers/mfd/dln2.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c
index 8311820..1be9bd1 100644
--- a/drivers/mfd/dln2.c
+++ b/drivers/mfd/dln2.c
@@ -791,6 +791,24 @@ out_free:
 	return ret;
 }

+static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
+{
+	struct dln2_dev *dln2 = usb_get_intfdata(iface);
+
+	dln2_stop(dln2);
+
+	return 0;
+}
+
+static int dln2_resume(struct usb_interface *iface)
+{
+	struct dln2_dev *dln2 = usb_get_intfdata(iface);
+
+	dln2->disconnect = false;
+
+	return dln2_start_rx_urbs(dln2, GFP_NOIO);
+}
+
 static const struct usb_device_id dln2_table[] = {
 	{ USB_DEVICE(0xa257, 0x2013) },
 	{ }
@@ -803,6 +821,8 @@ static struct usb_driver dln2_driver = {
 	.probe = dln2_probe,
 	.disconnect = dln2_disconnect,
 	.id_table = dln2_table,
+	.suspend = dln2_suspend,
+	.resume = dln2_resume,
 };

 module_usb_driver(dln2_driver);
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/