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Commit 86478944 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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[PATCH] USB: cdc-acm: add a new special case for modems with buggy firmware 



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: default avatarOliver Neukum <oliver@neukum.name>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 5cd330f4

drivers/usb/class/cdc-acm.c

+50 −32
Original line number Diff line number Diff line
@@ -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;

	}

}
@@ -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;

}
@@ -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);

}
@@ -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;



	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);

}
@@ -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);

	}
@@ -488,14 +497,15 @@ bail_out: 


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);

}
@@ -503,18 +513,19 @@ static void acm_tty_unregister(struct acm *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);
@@ -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)
@@ -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);

	}

}
@@ -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) {
@@ -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);
@@ -900,7 +915,7 @@ skip_normal_probe: 
	}



	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;
@@ -909,6 +924,7 @@ skip_normal_probe: 
	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);
@@ -935,7 +951,7 @@ skip_normal_probe: 
		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))) {
@@ -946,10 +962,9 @@ skip_normal_probe: 
		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;
@@ -988,9 +1003,9 @@ skip_normal_probe: 
	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:
@@ -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);
@@ -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);
@@ -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) },

drivers/usb/class/cdc-acm.h

+9 −7
Original line number Diff line number Diff line
@@ -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;
@@ -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;
@@ -122,3 +123,4 @@ struct acm { 


/* constants describing various quirks and errors */

#define NO_UNION_NORMAL			1

#define SINGLE_RX_URB			2