usb: mdm_bridge: Fix autosuspend for tethered connections
As ctrl_bridge_write() calls usb_autopm_get asynchronously, ensure that
the HSIC MDM device is out of suspend before attempting to write
control packets. Do this by deferring the URBs if the device is still
suspended and submit them in the resume callback.
In ctrl_bridge_start_read(), before submitting the interrupt URB the
device needs to be active. However, since this function may also be
called from the resume callback, it cannot call usb_autopm_get_interface
synchronously, so move the call to ctrl_bridge_open().
Eliminate ctrl_bridge_stop_read() by anchoring the interrupt and control
URBs along with the other write URBs. This simplifies when we need to
cancel them all en masse. Having them anchored also lets us know they
are in flight to avoid resubmitting them.
Finally, fix the suspend/resume callback functions to not rely on the
bridge being open and instead use the data_bridge's ID field to figure
out which ctrl_bridge device to call. This fixes inconsistent suspend
behavior when the bridge is closed, i.e. when the host tethered USB cable
is disconnected.
Change-Id: I9372f9a880639451b8b687dbb630172d7f5ef2d8
Signed-off-by: Jack Pham <jackp@codeaurora.org>
diff --git a/drivers/usb/misc/mdm_ctrl_bridge.c b/drivers/usb/misc/mdm_ctrl_bridge.c
index 584503a..c23c7b1 100644
--- a/drivers/usb/misc/mdm_ctrl_bridge.c
+++ b/drivers/usb/misc/mdm_ctrl_bridge.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+/* Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@@ -38,8 +38,9 @@
#define ACM_CTRL_DTR (1 << 0)
#define DEFAULT_READ_URB_LENGTH 4096
-struct ctrl_bridge {
+#define SUSPENDED BIT(0)
+struct ctrl_bridge {
struct usb_device *udev;
struct usb_interface *intf;
@@ -51,11 +52,14 @@
void *readbuf;
struct usb_anchor tx_submitted;
+ struct usb_anchor tx_deferred;
struct usb_ctrlrequest *in_ctlreq;
struct bridge *brdg;
struct platform_device *pdev;
+ unsigned long flags;
+
/* input control lines (DSR, CTS, CD, RI) */
unsigned int cbits_tohost;
@@ -68,7 +72,6 @@
unsigned int resp_avail;
unsigned int set_ctrl_line_sts;
unsigned int notify_ser_state;
-
};
static struct ctrl_bridge *__dev[MAX_BRIDGE_DEVICES];
@@ -157,11 +160,14 @@
if (resubmit_urb) {
/*re- submit int urb to check response available*/
+ usb_anchor_urb(dev->inturb, &dev->tx_submitted);
status = usb_submit_urb(dev->inturb, GFP_ATOMIC);
- if (status)
+ if (status) {
dev_err(&udev->dev,
"%s: Error re-submitting Int URB %d\n",
__func__, status);
+ usb_unanchor_urb(dev->inturb);
+ }
}
}
@@ -210,11 +216,13 @@
DEFAULT_READ_URB_LENGTH,
resp_avail_cb, dev);
+ usb_anchor_urb(dev->readurb, &dev->tx_submitted);
status = usb_submit_urb(dev->readurb, GFP_ATOMIC);
if (status) {
dev_err(&udev->dev,
"%s: Error submitting Read URB %d\n",
__func__, status);
+ usb_unanchor_urb(dev->readurb);
goto resubmit_int_urb;
}
return;
@@ -238,52 +246,42 @@
}
resubmit_int_urb:
+ usb_anchor_urb(urb, &dev->tx_submitted);
status = usb_submit_urb(urb, GFP_ATOMIC);
- if (status)
+ if (status) {
dev_err(&udev->dev, "%s: Error re-submitting Int URB %d\n",
__func__, status);
+ usb_unanchor_urb(urb);
+ }
}
int ctrl_bridge_start_read(struct ctrl_bridge *dev)
{
- int retval = 0;
- struct usb_device *udev;
+ int retval = 0;
- udev = interface_to_usbdev(dev->intf);
-
- retval = usb_autopm_get_interface_async(dev->intf);
- if (retval < 0) {
- dev_err(&udev->dev, "%s resumption fail\n", __func__);
- goto done_nopm;
+ if (!dev->inturb) {
+ dev_err(&dev->udev->dev, "%s: inturb is NULL\n", __func__);
+ return -ENODEV;
}
- retval = usb_submit_urb(dev->inturb, GFP_KERNEL);
- if (retval < 0)
- dev_err(&udev->dev, "%s intr submit %d\n", __func__, retval);
+ if (!dev->inturb->anchor) {
+ usb_anchor_urb(dev->inturb, &dev->tx_submitted);
+ retval = usb_submit_urb(dev->inturb, GFP_KERNEL);
+ if (retval < 0) {
+ dev_err(&dev->udev->dev,
+ "%s error submitting int urb %d\n",
+ __func__, retval);
+ usb_unanchor_urb(dev->inturb);
+ }
+ }
- usb_autopm_put_interface_async(dev->intf);
-done_nopm:
return retval;
}
-static int ctrl_bridge_stop_read(struct ctrl_bridge *dev)
-{
- if (dev->readurb) {
- dev_dbg(&dev->udev->dev, "killing rcv urb\n");
- usb_unlink_urb(dev->readurb);
- }
-
- if (dev->inturb) {
- dev_dbg(&dev->udev->dev, "killing int urb\n");
- usb_unlink_urb(dev->inturb);
- }
-
- return 0;
-}
-
int ctrl_bridge_open(struct bridge *brdg)
{
struct ctrl_bridge *dev;
+ int ret;
if (!brdg) {
err("bridge is null\n");
@@ -306,7 +304,16 @@
dev->set_ctrl_line_sts = 0;
dev->notify_ser_state = 0;
- return ctrl_bridge_start_read(dev);
+ ret = usb_autopm_get_interface(dev->intf);
+ if (ret < 0) {
+ dev_err(&dev->udev->dev, "%s autopm_get fail: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = ctrl_bridge_start_read(dev);
+ usb_autopm_put_interface(dev->intf);
+ return ret;
}
EXPORT_SYMBOL(ctrl_bridge_open);
@@ -325,7 +332,6 @@
ctrl_bridge_set_cbits(dev->brdg->ch_id, 0);
usb_unlink_anchored_urbs(&dev->tx_submitted);
- ctrl_bridge_stop_read(dev);
dev->brdg = NULL;
}
@@ -423,6 +429,11 @@
goto free_ctrlreq;
}
+ if (test_bit(SUSPENDED, &dev->flags)) {
+ usb_anchor_urb(writeurb, &dev->tx_deferred);
+ goto deferred;
+ }
+
usb_anchor_urb(writeurb, &dev->tx_submitted);
result = usb_submit_urb(writeurb, GFP_ATOMIC);
if (result < 0) {
@@ -431,7 +442,7 @@
usb_autopm_put_interface_async(dev->intf);
goto unanchor_urb;
}
-
+deferred:
return size;
unanchor_urb:
@@ -458,14 +469,16 @@
if (!dev)
return -ENODEV;
+ set_bit(SUSPENDED, &dev->flags);
usb_kill_anchored_urbs(&dev->tx_submitted);
- return ctrl_bridge_stop_read(dev);
+ return 0;
}
int ctrl_bridge_resume(unsigned int id)
{
struct ctrl_bridge *dev;
+ struct urb *urb;
if (id >= MAX_BRIDGE_DEVICES)
return -EINVAL;
@@ -474,7 +487,28 @@
if (!dev)
return -ENODEV;
- return ctrl_bridge_start_read(dev);
+ if (!test_and_clear_bit(SUSPENDED, &dev->flags))
+ return 0;
+
+ /* submit pending write requests */
+ while ((urb = usb_get_from_anchor(&dev->tx_deferred))) {
+ int ret;
+ usb_anchor_urb(urb, &dev->tx_submitted);
+ ret = usb_submit_urb(urb, GFP_ATOMIC);
+ if (ret < 0) {
+ usb_unanchor_urb(urb);
+ kfree(urb->setup_packet);
+ kfree(urb->transfer_buffer);
+ usb_free_urb(urb);
+ usb_autopm_put_interface_async(dev->intf);
+ }
+ }
+
+ /* if the bridge is open, resume reading */
+ if (dev->brdg)
+ return ctrl_bridge_start_read(dev);
+
+ return 0;
}
#if defined(CONFIG_DEBUG_FS)
@@ -505,7 +539,8 @@
"set ctrlline sts cnt: %u\n"
"notify ser state cnt: %u\n"
"cbits_tomdm: %d\n"
- "cbits_tohost: %d\n",
+ "cbits_tohost: %d\n"
+ "suspended: %d\n",
dev->pdev->name, dev,
dev->snd_encap_cmd,
dev->get_encap_res,
@@ -513,8 +548,8 @@
dev->set_ctrl_line_sts,
dev->notify_ser_state,
dev->cbits_tomdm,
- dev->cbits_tohost);
-
+ dev->cbits_tohost,
+ test_bit(SUSPENDED, &dev->flags));
}
ret = simple_read_from_buffer(ubuf, count, ppos, buf, temp);
@@ -608,6 +643,7 @@
dev->intf = ifc;
init_usb_anchor(&dev->tx_submitted);
+ init_usb_anchor(&dev->tx_deferred);
/*use max pkt size from ep desc*/
ep = &dev->intf->cur_altsetting->endpoint[0].desc;