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path: root/drivers/usb/class/cdc-wdm.c
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Diffstat (limited to 'drivers/usb/class/cdc-wdm.c')
-rw-r--r--drivers/usb/class/cdc-wdm.c113
1 files changed, 96 insertions, 17 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 5f0cb417b73..a051a7a2b1b 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -13,6 +13,7 @@
*/
#include <linux/kernel.h>
#include <linux/errno.h>
+#include <linux/ioctl.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mutex.h>
@@ -56,6 +57,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
#define WDM_RESPONDING 7
#define WDM_SUSPENDING 8
#define WDM_RESETTING 9
+#define WDM_OVERFLOW 10
#define WDM_MAX 16
@@ -99,6 +101,7 @@ struct wdm_device {
struct work_struct rxwork;
int werr;
int rerr;
+ int resp_count;
struct list_head device_list;
int (*manage_power)(struct usb_interface *, int);
@@ -155,6 +158,7 @@ static void wdm_in_callback(struct urb *urb)
{
struct wdm_device *desc = urb->context;
int status = urb->status;
+ int length = urb->actual_length;
spin_lock(&desc->iuspin);
clear_bit(WDM_RESPONDING, &desc->flags);
@@ -185,9 +189,17 @@ static void wdm_in_callback(struct urb *urb)
}
desc->rerr = status;
- desc->reslength = urb->actual_length;
- memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
- desc->length += desc->reslength;
+ if (length + desc->length > desc->wMaxCommand) {
+ /* The buffer would overflow */
+ set_bit(WDM_OVERFLOW, &desc->flags);
+ } else {
+ /* we may already be in overflow */
+ if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
+ memmove(desc->ubuf + desc->length, desc->inbuf, length);
+ desc->length += length;
+ desc->reslength = length;
+ }
+ }
skip_error:
wake_up(&desc->wait);
@@ -198,6 +210,7 @@ skip_error:
static void wdm_int_callback(struct urb *urb)
{
int rv = 0;
+ int responding;
int status = urb->status;
struct wdm_device *desc;
struct usb_cdc_notification *dr;
@@ -241,6 +254,10 @@ static void wdm_int_callback(struct urb *urb)
"NOTIFY_NETWORK_CONNECTION %s network",
dr->wValue ? "connected to" : "disconnected from");
goto exit;
+ case USB_CDC_NOTIFY_SPEED_CHANGE:
+ dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)",
+ urb->actual_length);
+ goto exit;
default:
clear_bit(WDM_POLL_RUNNING, &desc->flags);
dev_err(&desc->intf->dev,
@@ -250,9 +267,9 @@ static void wdm_int_callback(struct urb *urb)
}
spin_lock(&desc->iuspin);
- clear_bit(WDM_READ, &desc->flags);
- set_bit(WDM_RESPONDING, &desc->flags);
- if (!test_bit(WDM_DISCONNECTING, &desc->flags)
+ responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
+ if (!desc->resp_count++ && !responding
+ && !test_bit(WDM_DISCONNECTING, &desc->flags)
&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
rv = usb_submit_urb(desc->response, GFP_ATOMIC);
dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
@@ -415,6 +432,38 @@ outnl:
return rv < 0 ? rv : count;
}
+/*
+ * clear WDM_READ flag and possibly submit the read urb if resp_count
+ * is non-zero.
+ *
+ * Called with desc->iuspin locked
+ */
+static int clear_wdm_read_flag(struct wdm_device *desc)
+{
+ int rv = 0;
+
+ clear_bit(WDM_READ, &desc->flags);
+
+ /* submit read urb only if the device is waiting for it */
+ if (!desc->resp_count || !--desc->resp_count)
+ goto out;
+
+ set_bit(WDM_RESPONDING, &desc->flags);
+ spin_unlock_irq(&desc->iuspin);
+ rv = usb_submit_urb(desc->response, GFP_KERNEL);
+ spin_lock_irq(&desc->iuspin);
+ if (rv) {
+ dev_err(&desc->intf->dev,
+ "usb_submit_urb failed with result %d\n", rv);
+
+ /* make sure the next notification trigger a submit */
+ clear_bit(WDM_RESPONDING, &desc->flags);
+ desc->resp_count = 0;
+ }
+out:
+ return rv;
+}
+
static ssize_t wdm_read
(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
@@ -435,6 +484,11 @@ retry:
rv = -ENODEV;
goto err;
}
+ if (test_bit(WDM_OVERFLOW, &desc->flags)) {
+ clear_bit(WDM_OVERFLOW, &desc->flags);
+ rv = -ENOBUFS;
+ goto err;
+ }
i++;
if (file->f_flags & O_NONBLOCK) {
if (!test_bit(WDM_READ, &desc->flags)) {
@@ -478,10 +532,13 @@ retry:
spin_unlock_irq(&desc->iuspin);
goto retry;
}
+
if (!desc->reslength) { /* zero length read */
dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
- clear_bit(WDM_READ, &desc->flags);
+ rv = clear_wdm_read_flag(desc);
spin_unlock_irq(&desc->iuspin);
+ if (rv < 0)
+ goto err;
goto retry;
}
cntr = desc->length;
@@ -504,10 +561,8 @@ retry:
desc->length -= cntr;
/* in case we had outstanding data */
if (!desc->length)
- clear_bit(WDM_READ, &desc->flags);
-
+ clear_wdm_read_flag(desc);
spin_unlock_irq(&desc->iuspin);
-
rv = cntr;
err:
@@ -617,6 +672,9 @@ static int wdm_release(struct inode *inode, struct file *file)
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
kill_urbs(desc);
+ spin_lock_irq(&desc->iuspin);
+ desc->resp_count = 0;
+ spin_unlock_irq(&desc->iuspin);
desc->manage_power(desc->intf, 0);
} else {
/* must avoid dev_printk here as desc->intf is invalid */
@@ -628,6 +686,22 @@ static int wdm_release(struct inode *inode, struct file *file)
return 0;
}
+static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct wdm_device *desc = file->private_data;
+ int rv = 0;
+
+ switch (cmd) {
+ case IOCTL_WDM_MAX_COMMAND:
+ if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
+ rv = -EFAULT;
+ break;
+ default:
+ rv = -ENOTTY;
+ }
+ return rv;
+}
+
static const struct file_operations wdm_fops = {
.owner = THIS_MODULE,
.read = wdm_read,
@@ -636,6 +710,8 @@ static const struct file_operations wdm_fops = {
.flush = wdm_flush,
.release = wdm_release,
.poll = wdm_poll,
+ .unlocked_ioctl = wdm_ioctl,
+ .compat_ioctl = wdm_ioctl,
.llseek = noop_llseek,
};
@@ -650,16 +726,20 @@ static void wdm_rxwork(struct work_struct *work)
{
struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
unsigned long flags;
- int rv;
+ int rv = 0;
+ int responding;
spin_lock_irqsave(&desc->iuspin, flags);
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
spin_unlock_irqrestore(&desc->iuspin, flags);
} else {
+ responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
- rv = usb_submit_urb(desc->response, GFP_KERNEL);
+ if (!responding)
+ rv = usb_submit_urb(desc->response, GFP_KERNEL);
if (rv < 0 && rv != -EPERM) {
spin_lock_irqsave(&desc->iuspin, flags);
+ clear_bit(WDM_RESPONDING, &desc->flags);
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
schedule_work(&desc->rxwork);
spin_unlock_irqrestore(&desc->iuspin, flags);
@@ -780,13 +860,11 @@ static int wdm_manage_power(struct usb_interface *intf, int on)
{
/* need autopm_get/put here to ensure the usbcore sees the new value */
int rv = usb_autopm_get_interface(intf);
- if (rv < 0)
- goto err;
intf->needs_remote_wakeup = on;
- usb_autopm_put_interface(intf);
-err:
- return rv;
+ if (!rv)
+ usb_autopm_put_interface(intf);
+ return 0;
}
static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
@@ -1004,6 +1082,7 @@ static int wdm_post_reset(struct usb_interface *intf)
struct wdm_device *desc = wdm_find_device(intf);
int rv;
+ clear_bit(WDM_OVERFLOW, &desc->flags);
clear_bit(WDM_RESETTING, &desc->flags);
rv = recover_from_urb_loss(desc);
mutex_unlock(&desc->wlock);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 16:04:25 +0000