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[PATCH] USB: cdc-acm: add a new special case for modems with buggy fi…
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…rmware

this fixes the "duplicated text" bug. There's a modem that cannot cope
with large transfers and more than one urb in flight. This patch adds a
special case to the driver.

Signed-off-by: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Oliver Neukum authored and Greg Kroah-Hartman committed Jun 21, 2006
1 parent 5cd330f commit 8647894
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Showing 2 changed files with 59 additions and 39 deletions.
82 changes: 50 additions & 32 deletions drivers/usb/class/cdc-acm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -127,8 +127,8 @@ static int acm_wb_alloc(struct acm *acm)
wb->use = 1;
return wbn;
}
wbn = (wbn + 1) % ACM_NWB;
if (++i >= ACM_NWB)
wbn = (wbn + 1) % ACM_NW;
if (++i >= ACM_NW)
return -1;
}
}
Expand All @@ -142,10 +142,9 @@ static int acm_wb_is_avail(struct acm *acm)
{
int i, n;

n = 0;
for (i = 0; i < ACM_NWB; i++) {
if (!acm->wb[i].use)
n++;
n = ACM_NW;
for (i = 0; i < ACM_NW; i++) {
n -= acm->wb[i].use;
}
return n;
}
Expand All @@ -167,7 +166,7 @@ static void acm_write_done(struct acm *acm)
acm->write_ready = 1;
wbn = acm->write_current;
acm_wb_free(acm, wbn);
acm->write_current = (wbn + 1) % ACM_NWB;
acm->write_current = (wbn + 1) % ACM_NW;
spin_unlock_irqrestore(&acm->write_lock, flags);
}

Expand Down Expand Up @@ -291,22 +290,32 @@ static void acm_read_bulk(struct urb *urb, struct pt_regs *regs)
struct acm_rb *buf;
struct acm_ru *rcv = urb->context;
struct acm *acm = rcv->instance;
int status = urb->status;
dbg("Entering acm_read_bulk with status %d\n", urb->status);

if (!ACM_READY(acm))
return;

if (urb->status)
dev_dbg(&acm->data->dev, "bulk rx status %d\n", urb->status);
if (status)
dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);

buf = rcv->buffer;
buf->size = urb->actual_length;

spin_lock(&acm->read_lock);
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add_tail(&buf->list, &acm->filled_read_bufs);
spin_unlock(&acm->read_lock);

if (likely(status == 0)) {
spin_lock(&acm->read_lock);
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add_tail(&buf->list, &acm->filled_read_bufs);
spin_unlock(&acm->read_lock);
} else {
/* we drop the buffer due to an error */
spin_lock(&acm->read_lock);
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add(&buf->list, &acm->spare_read_bufs);
spin_unlock(&acm->read_lock);
/* nevertheless the tasklet must be kicked unconditionally
so the queue cannot dry up */
}
tasklet_schedule(&acm->urb_task);
}

Expand Down Expand Up @@ -464,10 +473,10 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
INIT_LIST_HEAD(&acm->spare_read_urbs);
INIT_LIST_HEAD(&acm->spare_read_bufs);
INIT_LIST_HEAD(&acm->filled_read_bufs);
for (i = 0; i < ACM_NRU; i++) {
for (i = 0; i < acm->rx_buflimit; i++) {
list_add(&(acm->ru[i].list), &acm->spare_read_urbs);
}
for (i = 0; i < ACM_NRB; i++) {
for (i = 0; i < acm->rx_buflimit; i++) {
list_add(&(acm->rb[i].list), &acm->spare_read_bufs);
}

Expand All @@ -488,33 +497,35 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)

static void acm_tty_unregister(struct acm *acm)
{
int i;
int i,nr;

nr = acm->rx_buflimit;
tty_unregister_device(acm_tty_driver, acm->minor);
usb_put_intf(acm->control);
acm_table[acm->minor] = NULL;
usb_free_urb(acm->ctrlurb);
usb_free_urb(acm->writeurb);
for (i = 0; i < ACM_NRU; i++)
for (i = 0; i < nr; i++)
usb_free_urb(acm->ru[i].urb);
kfree(acm);
}

static void acm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
int i;
int i,nr;

if (!acm || !acm->used)
return;

nr = acm->rx_buflimit;
mutex_lock(&open_mutex);
if (!--acm->used) {
if (acm->dev) {
acm_set_control(acm, acm->ctrlout = 0);
usb_kill_urb(acm->ctrlurb);
usb_kill_urb(acm->writeurb);
for (i = 0; i < ACM_NRU; i++)
for (i = 0; i < nr; i++)
usb_kill_urb(acm->ru[i].urb);
} else
acm_tty_unregister(acm);
Expand Down Expand Up @@ -576,7 +587,7 @@ static int acm_tty_chars_in_buffer(struct tty_struct *tty)
/*
* This is inaccurate (overcounts), but it works.
*/
return (ACM_NWB - acm_wb_is_avail(acm)) * acm->writesize;
return (ACM_NW - acm_wb_is_avail(acm)) * acm->writesize;
}

static void acm_tty_throttle(struct tty_struct *tty)
Expand Down Expand Up @@ -712,7 +723,7 @@ static void acm_write_buffers_free(struct acm *acm)
int i;
struct acm_wb *wb;

for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
usb_buffer_free(acm->dev, acm->writesize, wb->buf, wb->dmah);
}
}
Expand All @@ -723,7 +734,7 @@ static int acm_write_buffers_alloc(struct acm *acm)
int i;
struct acm_wb *wb;

for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
&wb->dmah);
if (!wb->buf) {
Expand Down Expand Up @@ -760,10 +771,14 @@ static int acm_probe (struct usb_interface *intf,
int call_interface_num = -1;
int data_interface_num;
unsigned long quirks;
int num_rx_buf;
int i;

/* handle quirks deadly to normal probing*/
/* normal quirks */
quirks = (unsigned long)id->driver_info;
num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;

/* handle quirks deadly to normal probing*/
if (quirks == NO_UNION_NORMAL) {
data_interface = usb_ifnum_to_if(usb_dev, 1);
control_interface = usb_ifnum_to_if(usb_dev, 0);
Expand Down Expand Up @@ -900,7 +915,7 @@ static int acm_probe (struct usb_interface *intf,
}

ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
readsize = le16_to_cpu(epread->wMaxPacketSize)*2;
readsize = le16_to_cpu(epread->wMaxPacketSize)* ( quirks == SINGLE_RX_URB ? 1 : 2);
acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize);
acm->control = control_interface;
acm->data = data_interface;
Expand All @@ -909,6 +924,7 @@ static int acm_probe (struct usb_interface *intf,
acm->ctrl_caps = ac_management_function;
acm->ctrlsize = ctrlsize;
acm->readsize = readsize;
acm->rx_buflimit = num_rx_buf;
acm->urb_task.func = acm_rx_tasklet;
acm->urb_task.data = (unsigned long) acm;
INIT_WORK(&acm->work, acm_softint, acm);
Expand All @@ -935,7 +951,7 @@ static int acm_probe (struct usb_interface *intf,
dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
goto alloc_fail5;
}
for (i = 0; i < ACM_NRU; i++) {
for (i = 0; i < num_rx_buf; i++) {
struct acm_ru *rcv = &(acm->ru[i]);

if (!(rcv->urb = usb_alloc_urb(0, GFP_KERNEL))) {
Expand All @@ -946,10 +962,9 @@ static int acm_probe (struct usb_interface *intf,
rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
rcv->instance = acm;
}
for (i = 0; i < ACM_NRB; i++) {
for (i = 0; i < num_rx_buf; i++) {
struct acm_rb *buf = &(acm->rb[i]);

// Using usb_buffer_alloc instead of kmalloc as Oliver suggested
if (!(buf->base = usb_buffer_alloc(acm->dev, readsize, GFP_KERNEL, &buf->dma))) {
dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
goto alloc_fail7;
Expand Down Expand Up @@ -988,9 +1003,9 @@ static int acm_probe (struct usb_interface *intf,
return 0;

alloc_fail7:
for (i = 0; i < ACM_NRB; i++)
for (i = 0; i < num_rx_buf; i++)
usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
for (i = 0; i < ACM_NRU; i++)
for (i = 0; i < num_rx_buf; i++)
usb_free_urb(acm->ru[i].urb);
usb_free_urb(acm->ctrlurb);
alloc_fail5:
Expand Down Expand Up @@ -1027,7 +1042,7 @@ static void acm_disconnect(struct usb_interface *intf)

usb_kill_urb(acm->ctrlurb);
usb_kill_urb(acm->writeurb);
for (i = 0; i < ACM_NRU; i++)
for (i = 0; i < acm->rx_buflimit; i++)
usb_kill_urb(acm->ru[i].urb);

INIT_LIST_HEAD(&acm->filled_read_bufs);
Expand All @@ -1039,7 +1054,7 @@ static void acm_disconnect(struct usb_interface *intf)

acm_write_buffers_free(acm);
usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
for (i = 0; i < ACM_NRB; i++)
for (i = 0; i < acm->rx_buflimit; i++)
usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);

usb_driver_release_interface(&acm_driver, intf == acm->control ? acm->data : intf);
Expand Down Expand Up @@ -1068,6 +1083,9 @@ static struct usb_device_id acm_ids[] = {
{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
.driver_info = SINGLE_RX_URB, /* firmware bug */
},
/* control interfaces with various AT-command sets */
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_V25TER) },
Expand Down
16 changes: 9 additions & 7 deletions drivers/usb/class/cdc-acm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,11 +56,11 @@
* in line disciplines. They ask for empty space amount, receive our URB size,
* and proceed to issue several 1-character writes, assuming they will fit.
* The very first write takes a complete URB. Fortunately, this only happens
* when processing onlcr, so we only need 2 buffers.
* when processing onlcr, so we only need 2 buffers. These values must be
* powers of 2.
*/
#define ACM_NWB 2
#define ACM_NRU 16
#define ACM_NRB 16
#define ACM_NW 2
#define ACM_NR 16

struct acm_wb {
unsigned char *buf;
Expand Down Expand Up @@ -91,9 +91,10 @@ struct acm {
struct urb *ctrlurb, *writeurb; /* urbs */
u8 *ctrl_buffer; /* buffers of urbs */
dma_addr_t ctrl_dma; /* dma handles of buffers */
struct acm_wb wb[ACM_NWB];
struct acm_ru ru[ACM_NRU];
struct acm_rb rb[ACM_NRB];
struct acm_wb wb[ACM_NW];
struct acm_ru ru[ACM_NR];
struct acm_rb rb[ACM_NR];
int rx_buflimit;
int rx_endpoint;
spinlock_t read_lock;
struct list_head spare_read_urbs;
Expand Down Expand Up @@ -122,3 +123,4 @@ struct acm {

/* constants describing various quirks and errors */
#define NO_UNION_NORMAL 1
#define SINGLE_RX_URB 2

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