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Diffstat (limited to 'drivers/usb/class')
-rw-r--r--drivers/usb/class/cdc-acm.c157
-rw-r--r--drivers/usb/class/cdc-acm.h1
-rw-r--r--drivers/usb/class/cdc-wdm.c195
-rw-r--r--drivers/usb/class/usbtmc.c11
4 files changed, 196 insertions, 168 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 94a14f5dc4d4..78f0f85bebdc 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -368,17 +368,17 @@ static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags)
if (!test_and_clear_bit(index, &acm->read_urbs_free))
return 0;
- dev_vdbg(&acm->data->dev, "%s - urb %d\n", __func__, index);
-
res = usb_submit_urb(acm->read_urbs[index], mem_flags);
if (res) {
if (res != -EPERM) {
dev_err(&acm->data->dev,
- "%s - usb_submit_urb failed: %d\n",
- __func__, res);
+ "urb %d failed submission with %d\n",
+ index, res);
}
set_bit(index, &acm->read_urbs_free);
return res;
+ } else {
+ dev_vdbg(&acm->data->dev, "submitted urb %d\n", index);
}
return 0;
@@ -415,8 +415,9 @@ static void acm_read_bulk_callback(struct urb *urb)
unsigned long flags;
int status = urb->status;
- dev_vdbg(&acm->data->dev, "%s - urb %d, len %d\n", __func__,
- rb->index, urb->actual_length);
+ dev_vdbg(&acm->data->dev, "got urb %d, len %d, status %d\n",
+ rb->index, urb->actual_length,
+ status);
if (!acm->dev) {
set_bit(rb->index, &acm->read_urbs_free);
@@ -426,8 +427,6 @@ static void acm_read_bulk_callback(struct urb *urb)
if (status) {
set_bit(rb->index, &acm->read_urbs_free);
- dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
- __func__, status);
if ((status != -ENOENT) || (urb->actual_length == 0))
return;
}
@@ -462,8 +461,7 @@ static void acm_write_bulk(struct urb *urb)
int status = urb->status;
if (status || (urb->actual_length != urb->transfer_buffer_length))
- dev_vdbg(&acm->data->dev, "%s - len %d/%d, status %d\n",
- __func__,
+ dev_vdbg(&acm->data->dev, "wrote len %d/%d, status %d\n",
urb->actual_length,
urb->transfer_buffer_length,
status);
@@ -478,8 +476,6 @@ static void acm_softint(struct work_struct *work)
{
struct acm *acm = container_of(work, struct acm, work);
- dev_vdbg(&acm->data->dev, "%s\n", __func__);
-
tty_port_tty_wakeup(&acm->port);
}
@@ -492,8 +488,6 @@ static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
struct acm *acm;
int retval;
- dev_dbg(tty->dev, "%s\n", __func__);
-
acm = acm_get_by_minor(tty->index);
if (!acm)
return -ENODEV;
@@ -515,8 +509,6 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
- dev_dbg(tty->dev, "%s\n", __func__);
-
return tty_port_open(&acm->port, tty, filp);
}
@@ -545,8 +537,6 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
int retval = -ENODEV;
int i;
- dev_dbg(&acm->control->dev, "%s\n", __func__);
-
mutex_lock(&acm->mutex);
if (acm->disconnected)
goto disconnected;
@@ -607,8 +597,6 @@ static void acm_port_destruct(struct tty_port *port)
{
struct acm *acm = container_of(port, struct acm, port);
- dev_dbg(&acm->control->dev, "%s\n", __func__);
-
acm_release_minor(acm);
usb_put_intf(acm->control);
kfree(acm->country_codes);
@@ -622,8 +610,6 @@ static void acm_port_shutdown(struct tty_port *port)
struct acm_wb *wb;
int i;
- dev_dbg(&acm->control->dev, "%s\n", __func__);
-
/*
* Need to grab write_lock to prevent race with resume, but no need to
* hold it due to the tty-port initialised flag.
@@ -654,21 +640,21 @@ static void acm_port_shutdown(struct tty_port *port)
static void acm_tty_cleanup(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
- dev_dbg(&acm->control->dev, "%s\n", __func__);
+
tty_port_put(&acm->port);
}
static void acm_tty_hangup(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
- dev_dbg(&acm->control->dev, "%s\n", __func__);
+
tty_port_hangup(&acm->port);
}
static void acm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
- dev_dbg(&acm->control->dev, "%s\n", __func__);
+
tty_port_close(&acm->port, tty, filp);
}
@@ -684,7 +670,7 @@ static int acm_tty_write(struct tty_struct *tty,
if (!count)
return 0;
- dev_vdbg(&acm->data->dev, "%s - count %d\n", __func__, count);
+ dev_vdbg(&acm->data->dev, "%d bytes from tty layer\n", count);
spin_lock_irqsave(&acm->write_lock, flags);
wbn = acm_wb_alloc(acm);
@@ -701,7 +687,7 @@ static int acm_tty_write(struct tty_struct *tty,
}
count = (count > acm->writesize) ? acm->writesize : count;
- dev_vdbg(&acm->data->dev, "%s - write %d\n", __func__, count);
+ dev_vdbg(&acm->data->dev, "writing %d bytes\n", count);
memcpy(wb->buf, buf, count);
wb->len = count;
@@ -946,7 +932,7 @@ static int wait_serial_change(struct acm *acm, unsigned long arg)
DECLARE_WAITQUEUE(wait, current);
struct async_icount old, new;
- if (arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD ))
+ if (arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD))
return -EINVAL;
do {
spin_lock_irq(&acm->read_lock);
@@ -1146,7 +1132,7 @@ static int acm_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct usb_cdc_union_desc *union_header = NULL;
- struct usb_cdc_country_functional_desc *cfd = NULL;
+ struct usb_cdc_call_mgmt_descriptor *cmgmd = NULL;
unsigned char *buffer = intf->altsetting->extra;
int buflen = intf->altsetting->extralen;
struct usb_interface *control_interface;
@@ -1155,18 +1141,16 @@ static int acm_probe(struct usb_interface *intf,
struct usb_endpoint_descriptor *epread = NULL;
struct usb_endpoint_descriptor *epwrite = NULL;
struct usb_device *usb_dev = interface_to_usbdev(intf);
+ struct usb_cdc_parsed_header h;
struct acm *acm;
int minor;
int ctrlsize, readsize;
u8 *buf;
- u8 ac_management_function = 0;
- u8 call_management_function = 0;
- int call_interface_num = -1;
- int data_interface_num = -1;
+ int call_intf_num = -1;
+ int data_intf_num = -1;
unsigned long quirks;
int num_rx_buf;
int i;
- unsigned int elength = 0;
int combined_interfaces = 0;
struct device *tty_dev;
int rv = -ENOMEM;
@@ -1195,6 +1179,9 @@ static int acm_probe(struct usb_interface *intf,
return -EINVAL;
}
+ if (!intf->cur_altsetting)
+ return -EINVAL;
+
if (!buflen) {
if (intf->cur_altsetting->endpoint &&
intf->cur_altsetting->endpoint->extralen &&
@@ -1210,70 +1197,22 @@ static int acm_probe(struct usb_interface *intf,
}
}
- while (buflen > 0) {
- elength = buffer[0];
- if (!elength) {
- dev_err(&intf->dev, "skipping garbage byte\n");
- elength = 1;
- goto next_desc;
- }
- if (buffer[1] != USB_DT_CS_INTERFACE) {
- dev_err(&intf->dev, "skipping garbage\n");
- goto next_desc;
- }
-
- switch (buffer[2]) {
- case USB_CDC_UNION_TYPE: /* we've found it */
- if (elength < sizeof(struct usb_cdc_union_desc))
- goto next_desc;
- if (union_header) {
- dev_err(&intf->dev, "More than one "
- "union descriptor, skipping ...\n");
- goto next_desc;
- }
- union_header = (struct usb_cdc_union_desc *)buffer;
- break;
- case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/
- if (elength < sizeof(struct usb_cdc_country_functional_desc))
- goto next_desc;
- cfd = (struct usb_cdc_country_functional_desc *)buffer;
- break;
- case USB_CDC_HEADER_TYPE: /* maybe check version */
- break; /* for now we ignore it */
- case USB_CDC_ACM_TYPE:
- if (elength < 4)
- goto next_desc;
- ac_management_function = buffer[3];
- break;
- case USB_CDC_CALL_MANAGEMENT_TYPE:
- if (elength < 5)
- goto next_desc;
- call_management_function = buffer[3];
- call_interface_num = buffer[4];
- break;
- default:
- /*
- * there are LOTS more CDC descriptors that
- * could legitimately be found here.
- */
- dev_dbg(&intf->dev, "Ignoring descriptor: "
- "type %02x, length %ud\n",
- buffer[2], elength);
- break;
- }
-next_desc:
- buflen -= elength;
- buffer += elength;
- }
+ cdc_parse_cdc_header(&h, intf, buffer, buflen);
+ union_header = h.usb_cdc_union_desc;
+ cmgmd = h.usb_cdc_call_mgmt_descriptor;
+ if (cmgmd)
+ call_intf_num = cmgmd->bDataInterface;
if (!union_header) {
- if (call_interface_num > 0) {
+ if (call_intf_num > 0) {
dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
/* quirks for Droids MuIn LCD */
- if (quirks & NO_DATA_INTERFACE)
+ if (quirks & NO_DATA_INTERFACE) {
data_interface = usb_ifnum_to_if(usb_dev, 0);
- else
- data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
+ } else {
+ data_intf_num = call_intf_num;
+ data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
+ }
control_interface = intf;
} else {
if (intf->cur_altsetting->desc.bNumEndpoints != 3) {
@@ -1287,16 +1226,19 @@ next_desc:
}
}
} else {
+ data_intf_num = union_header->bSlaveInterface0;
control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
- data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
+ data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
}
if (!control_interface || !data_interface) {
dev_dbg(&intf->dev, "no interfaces\n");
return -ENODEV;
}
+ if (!data_interface->cur_altsetting || !control_interface->cur_altsetting)
+ return -ENODEV;
- if (data_interface_num != call_interface_num)
+ if (data_intf_num != call_intf_num)
dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");
if (control_interface == data_interface) {
@@ -1379,11 +1321,8 @@ made_compressed_probe:
goto alloc_fail;
minor = acm_alloc_minor(acm);
- if (minor < 0) {
- dev_err(&intf->dev, "no more free acm devices\n");
- kfree(acm);
- return -ENODEV;
- }
+ if (minor < 0)
+ goto alloc_fail1;
ctrlsize = usb_endpoint_maxp(epctrl);
readsize = usb_endpoint_maxp(epread) *
@@ -1394,7 +1333,8 @@ made_compressed_probe:
acm->data = data_interface;
acm->minor = minor;
acm->dev = usb_dev;
- acm->ctrl_caps = ac_management_function;
+ if (h.usb_cdc_acm_descriptor)
+ acm->ctrl_caps = h.usb_cdc_acm_descriptor->bmCapabilities;
if (quirks & NO_CAP_LINE)
acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
acm->ctrlsize = ctrlsize;
@@ -1405,7 +1345,6 @@ made_compressed_probe:
spin_lock_init(&acm->write_lock);
spin_lock_init(&acm->read_lock);
mutex_init(&acm->mutex);
- acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
acm->is_int_ep = usb_endpoint_xfer_int(epread);
if (acm->is_int_ep)
acm->bInterval = epread->bInterval;
@@ -1445,14 +1384,14 @@ made_compressed_probe:
urb->transfer_dma = rb->dma;
if (acm->is_int_ep) {
usb_fill_int_urb(urb, acm->dev,
- acm->rx_endpoint,
+ usb_rcvintpipe(usb_dev, epread->bEndpointAddress),
rb->base,
acm->readsize,
acm_read_bulk_callback, rb,
acm->bInterval);
} else {
usb_fill_bulk_urb(urb, acm->dev,
- acm->rx_endpoint,
+ usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress),
rb->base,
acm->readsize,
acm_read_bulk_callback, rb);
@@ -1488,7 +1427,10 @@ made_compressed_probe:
if (i < 0)
goto alloc_fail7;
- if (cfd) { /* export the country data */
+ if (h.usb_cdc_country_functional_desc) { /* export the country data */
+ struct usb_cdc_country_functional_desc * cfd =
+ h.usb_cdc_country_functional_desc;
+
acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
if (!acm->country_codes)
goto skip_countries;
@@ -1572,6 +1514,7 @@ alloc_fail4:
usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
alloc_fail2:
acm_release_minor(acm);
+alloc_fail1:
kfree(acm);
alloc_fail:
return rv;
@@ -1581,8 +1524,6 @@ static void stop_data_traffic(struct acm *acm)
{
int i;
- dev_dbg(&acm->control->dev, "%s\n", __func__);
-
usb_kill_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_kill_urb(acm->wb[i].urb);
@@ -1599,8 +1540,6 @@ static void acm_disconnect(struct usb_interface *intf)
struct tty_struct *tty;
int i;
- dev_dbg(&intf->dev, "%s\n", __func__);
-
/* sibling interface is already cleaning up */
if (!acm)
return;
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index 05ce308d5d2a..1f1eabfd8462 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -96,7 +96,6 @@ struct acm {
struct acm_rb read_buffers[ACM_NR];
struct acm_wb *putbuffer; /* for acm_tty_put_char() */
int rx_buflimit;
- int rx_endpoint;
spinlock_t read_lock;
int write_used; /* number of non-empty write buffers */
int transmitting;
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 61ea87917433..0a6369510f2d 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -58,6 +58,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
#define WDM_SUSPENDING 8
#define WDM_RESETTING 9
#define WDM_OVERFLOW 10
+#define WDM_DRAIN_ON_OPEN 11
#define WDM_MAX 16
@@ -154,6 +155,9 @@ static void wdm_out_callback(struct urb *urb)
wake_up(&desc->wait);
}
+/* forward declaration */
+static int service_outstanding_interrupt(struct wdm_device *desc);
+
static void wdm_in_callback(struct urb *urb)
{
struct wdm_device *desc = urb->context;
@@ -167,18 +171,18 @@ static void wdm_in_callback(struct urb *urb)
switch (status) {
case -ENOENT:
dev_dbg(&desc->intf->dev,
- "nonzero urb status received: -ENOENT");
+ "nonzero urb status received: -ENOENT\n");
goto skip_error;
case -ECONNRESET:
dev_dbg(&desc->intf->dev,
- "nonzero urb status received: -ECONNRESET");
+ "nonzero urb status received: -ECONNRESET\n");
goto skip_error;
case -ESHUTDOWN:
dev_dbg(&desc->intf->dev,
- "nonzero urb status received: -ESHUTDOWN");
+ "nonzero urb status received: -ESHUTDOWN\n");
goto skip_error;
case -EPIPE:
- dev_err(&desc->intf->dev,
+ dev_dbg(&desc->intf->dev,
"nonzero urb status received: -EPIPE\n");
break;
default:
@@ -188,7 +192,13 @@ static void wdm_in_callback(struct urb *urb)
}
}
- desc->rerr = status;
+ /*
+ * only set a new error if there is no previous error.
+ * Errors are only cleared during read/open
+ */
+ if (desc->rerr == 0)
+ desc->rerr = status;
+
if (length + desc->length > desc->wMaxCommand) {
/* The buffer would overflow */
set_bit(WDM_OVERFLOW, &desc->flags);
@@ -200,10 +210,40 @@ static void wdm_in_callback(struct urb *urb)
desc->reslength = length;
}
}
+
+ /*
+ * Handling devices with the WDM_DRAIN_ON_OPEN flag set:
+ * If desc->resp_count is unset, then the urb was submitted
+ * without a prior notification. If the device returned any
+ * data, then this implies that it had messages queued without
+ * notifying us. Continue reading until that queue is flushed.
+ */
+ if (!desc->resp_count) {
+ if (!length) {
+ /* do not propagate the expected -EPIPE */
+ desc->rerr = 0;
+ goto unlock;
+ }
+ dev_dbg(&desc->intf->dev, "got %d bytes without notification\n", length);
+ set_bit(WDM_RESPONDING, &desc->flags);
+ usb_submit_urb(desc->response, GFP_ATOMIC);
+ }
+
skip_error:
+ set_bit(WDM_READ, &desc->flags);
wake_up(&desc->wait);
- set_bit(WDM_READ, &desc->flags);
+ if (desc->rerr) {
+ /*
+ * Since there was an error, userspace may decide to not read
+ * any data after poll'ing.
+ * We should respond to further attempts from the device to send
+ * data, so that we can get unstuck.
+ */
+ service_outstanding_interrupt(desc);
+ }
+
+unlock:
spin_unlock(&desc->iuspin);
}
@@ -244,18 +284,18 @@ static void wdm_int_callback(struct urb *urb)
switch (dr->bNotificationType) {
case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
dev_dbg(&desc->intf->dev,
- "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
+ "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
break;
case USB_CDC_NOTIFY_NETWORK_CONNECTION:
dev_dbg(&desc->intf->dev,
- "NOTIFY_NETWORK_CONNECTION %s network",
+ "NOTIFY_NETWORK_CONNECTION %s network\n",
dr->wValue ? "connected to" : "disconnected from");
goto exit;
case USB_CDC_NOTIFY_SPEED_CHANGE:
- dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)",
+ dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
urb->actual_length);
goto exit;
default:
@@ -274,8 +314,7 @@ static void wdm_int_callback(struct urb *urb)
&& !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",
- __func__, rv);
+ dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
}
spin_unlock(&desc->iuspin);
if (rv < 0) {
@@ -417,7 +456,7 @@ static ssize_t wdm_write
rv = usb_translate_errors(rv);
goto out_free_mem_pm;
} else {
- dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
+ dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
le16_to_cpu(req->wIndex));
}
@@ -436,17 +475,14 @@ out_free_mem:
}
/*
- * clear WDM_READ flag and possibly submit the read urb if resp_count
- * is non-zero.
+ * 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)
+static int service_outstanding_interrupt(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;
@@ -537,8 +573,9 @@ retry:
}
if (!desc->reslength) { /* zero length read */
- dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
- rv = clear_wdm_read_flag(desc);
+ dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
+ clear_bit(WDM_READ, &desc->flags);
+ rv = service_outstanding_interrupt(desc);
spin_unlock_irq(&desc->iuspin);
if (rv < 0)
goto err;
@@ -563,8 +600,10 @@ retry:
desc->length -= cntr;
/* in case we had outstanding data */
- if (!desc->length)
- clear_wdm_read_flag(desc);
+ if (!desc->length) {
+ clear_bit(WDM_READ, &desc->flags);
+ service_outstanding_interrupt(desc);
+ }
spin_unlock_irq(&desc->iuspin);
rv = cntr;
@@ -647,6 +686,17 @@ static int wdm_open(struct inode *inode, struct file *file)
dev_err(&desc->intf->dev,
"Error submitting int urb - %d\n", rv);
rv = usb_translate_errors(rv);
+ } else if (test_bit(WDM_DRAIN_ON_OPEN, &desc->flags)) {
+ /*
+ * Some devices keep pending messages queued
+ * without resending notifications. We must
+ * flush the message queue before we can
+ * assume a one-to-one relationship between
+ * notifications and messages in the queue
+ */
+ dev_dbg(&desc->intf->dev, "draining queued data\n");
+ set_bit(WDM_RESPONDING, &desc->flags);
+ rv = usb_submit_urb(desc->response, GFP_KERNEL);
}
} else {
rv = 0;
@@ -673,7 +723,7 @@ static int wdm_release(struct inode *inode, struct file *file)
if (!desc->count) {
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
- dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
+ dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
kill_urbs(desc);
spin_lock_irq(&desc->iuspin);
desc->resp_count = 0;
@@ -753,7 +803,8 @@ static void wdm_rxwork(struct work_struct *work)
/* --- hotplug --- */
static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
- u16 bufsize, int (*manage_power)(struct usb_interface *, int))
+ u16 bufsize, int (*manage_power)(struct usb_interface *, int),
+ bool drain_on_open)
{
int rv = -ENOMEM;
struct wdm_device *desc;
@@ -840,6 +891,68 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
desc->manage_power = manage_power;
+ /*
+ * "drain_on_open" enables a hack to work around a firmware
+ * issue observed on network functions, in particular MBIM
+ * functions.
+ *
+ * Quoting section 7 of the CDC-WMC r1.1 specification:
+ *
+ * "The firmware shall interpret GetEncapsulatedResponse as a
+ * request to read response bytes. The firmware shall send
+ * the next wLength bytes from the response. The firmware
+ * shall allow the host to retrieve data using any number of
+ * GetEncapsulatedResponse requests. The firmware shall
+ * return a zero- length reply if there are no data bytes
+ * available.
+ *
+ * The firmware shall send ResponseAvailable notifications
+ * periodically, using any appropriate algorithm, to inform
+ * the host that there is data available in the reply
+ * buffer. The firmware is allowed to send ResponseAvailable
+ * notifications even if there is no data available, but
+ * this will obviously reduce overall performance."
+ *
+ * These requirements, although they make equally sense, are
+ * often not implemented by network functions. Some firmwares
+ * will queue data indefinitely, without ever resending a
+ * notification. The result is that the driver and firmware
+ * loses "syncronization" if the driver ever fails to respond
+ * to a single notification, something which easily can happen
+ * on release(). When this happens, the driver will appear to
+ * never receive notifications for the most current data. Each
+ * notification will only cause a single read, which returns
+ * the oldest data in the firmware's queue.
+ *
+ * The "drain_on_open" hack resolves the situation by draining
+ * data from the firmware until none is returned, without a
+ * prior notification.
+ *
+ * This will inevitably race with the firmware, risking that
+ * we read data from the device before handling the associated
+ * notification. To make things worse, some of the devices
+ * needing the hack do not implement the "return zero if no
+ * data is available" requirement either. Instead they return
+ * an error on the subsequent read in this case. This means
+ * that "winning" the race can cause an unexpected EIO to
+ * userspace.
+ *
+ * "winning" the race is more likely on resume() than on
+ * open(), and the unexpected error is more harmful in the
+ * middle of an open session. The hack is therefore only
+ * applied on open(), and not on resume() where it logically
+ * would be equally necessary. So we define open() as the only
+ * driver <-> device "syncronization point". Should we happen
+ * to lose a notification after open(), then syncronization
+ * will be lost until release()
+ *
+ * The hack should not be enabled for CDC WDM devices
+ * conforming to the CDC-WMC r1.1 specification. This is
+ * ensured by setting drain_on_open to false in wdm_probe().
+ */
+ if (drain_on_open)
+ set_bit(WDM_DRAIN_ON_OPEN, &desc->flags);
+
spin_lock(&wdm_device_list_lock);
list_add(&desc->device_list, &wdm_device_list);
spin_unlock(&wdm_device_list_lock);
@@ -875,45 +988,25 @@ static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
int rv = -EINVAL;
struct usb_host_interface *iface;
struct usb_endpoint_descriptor *ep;
- struct usb_cdc_dmm_desc *dmhd;
+ struct usb_cdc_parsed_header hdr;
u8 *buffer = intf->altsetting->extra;
int buflen = intf->altsetting->extralen;
u16 maxcom = WDM_DEFAULT_BUFSIZE;
if (!buffer)
goto err;
- while (buflen > 2) {
- if (buffer[1] != USB_DT_CS_INTERFACE) {
- dev_err(&intf->dev, "skipping garbage\n");
- goto next_desc;
- }
- switch (buffer[2]) {
- case USB_CDC_HEADER_TYPE:
- break;
- case USB_CDC_DMM_TYPE:
- dmhd = (struct usb_cdc_dmm_desc *)buffer;
- maxcom = le16_to_cpu(dmhd->wMaxCommand);
- dev_dbg(&intf->dev,
- "Finding maximum buffer length: %d", maxcom);
- break;
- default:
- dev_err(&intf->dev,
- "Ignoring extra header, type %d, length %d\n",
- buffer[2], buffer[0]);
- break;
- }
-next_desc:
- buflen -= buffer[0];
- buffer += buffer[0];
- }
+ cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
+
+ if (hdr.usb_cdc_dmm_desc)
+ maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
iface = intf->cur_altsetting;
if (iface->desc.bNumEndpoints != 1)
goto err;
ep = &iface->endpoint[0].desc;
- rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
+ rv = wdm_create(intf, ep, maxcom, &wdm_manage_power, false);
err:
return rv;
@@ -945,7 +1038,7 @@ struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
{
int rv = -EINVAL;
- rv = wdm_create(intf, ep, bufsize, manage_power);
+ rv = wdm_create(intf, ep, bufsize, manage_power, true);
if (rv < 0)
goto err;
@@ -987,7 +1080,7 @@ static void wdm_disconnect(struct usb_interface *intf)
if (!desc->count)
cleanup(desc);
else
- dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
+ dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
mutex_unlock(&wdm_mutex);
}
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 917a55c4480d..a6c1fae7d52a 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -141,6 +141,7 @@ static void usbtmc_delete(struct kref *kref)
struct usbtmc_device_data *data = to_usbtmc_data(kref);
usb_put_dev(data->usb_dev);
+ kfree(data);
}
static int usbtmc_open(struct inode *inode, struct file *filp)
@@ -1379,7 +1380,7 @@ static int usbtmc_probe(struct usb_interface *intf,
dev_dbg(&intf->dev, "%s called\n", __func__);
- data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
@@ -1467,10 +1468,8 @@ static int usbtmc_probe(struct usb_interface *intf,
if (data->iin_ep_present) {
/* allocate int urb */
data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
- if (!data->iin_urb) {
- dev_err(&intf->dev, "Failed to allocate int urb\n");
+ if (!data->iin_urb)
goto error_register;
- }
/* will reference data in int urb */
kref_get(&data->kref);
@@ -1478,10 +1477,8 @@ static int usbtmc_probe(struct usb_interface *intf,
/* allocate buffer for interrupt in */
data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
GFP_KERNEL);
- if (!data->iin_buffer) {
- dev_err(&intf->dev, "Failed to allocate int buf\n");
+ if (!data->iin_buffer)
goto error_register;
- }
/* fill interrupt urb */
usb_fill_int_urb(data->iin_urb, data->usb_dev,
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