This patch was adapted from one posted by Ulmo on
http://www.evdoforums.com/about810.html
With this patch, I was able to realize speeds of 800kbps using Verizon
Wireless's PC5740 Aircard. This patch was adapted for the RHEL4 kernel
2.6.9. A howto will be posted soon on how this was done.
I am not sure how to get this evaluated for inclusion to the upstream
kernel so I am posting here. Any help is much appreciated.
I was also unable to find an email address for the original poster on
the forum list so forgive me if credit isn't attributed correctly.
Ivan
diff -u -r linux-2.6.9/drivers/usb/class/cdc-acm.c linux-2.6.9-6.34.EL/drivers/usb/class/cdc-acm.c
--- linux-2.6.9/drivers/usb/class/cdc-acm.c 2004-10-18 17:54:37.000000000 -0400
+++ linux-2.6.9-6.34.EL/drivers/usb/class/cdc-acm.c 2006-06-21 15:45:29.000000000 -0400
@@ -72,6 +72,7 @@
#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik"
#define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
+static ushort maxszc = 0, maxszw = 0, maxszr = 0;
static struct usb_driver acm_driver;
static struct tty_driver *acm_tty_driver;
static struct acm *acm_table[ACM_TTY_MINORS];
@@ -102,6 +103,113 @@
#define acm_send_break(acm, ms) acm_ctrl_msg(acm, ACM_REQ_SEND_BREAK, ms, NULL, 0)
/*
+ * Write buffer management.
+ * All of these assume proper locks taken by the caller.
+ */
+
+static int acm_wb_alloc(struct acm *acm)
+{
+ int i, wbn;
+ struct acm_wb *wb;
+
+ wbn = acm->write_current;
+ i = 0;
+ for (;;) {
+ wb = &acm->wb[wbn];
+ if (!wb->use) {
+ wb->use = 1;
+ return wbn;
+ }
+ wbn = (wbn + 1) % ACM_NWB;
+ if (++i >= ACM_NWB)
+ return -1;
+ }
+}
+
+static void acm_wb_free(struct acm *acm, int wbn)
+{
+ struct acm_wb *wb = &acm->wb[wbn];
+ wb->use = 0;
+ wb->len = 0;
+}
+
+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++;
+ }
+ return n;
+}
+
+static inline int acm_wb_is_used(struct acm *acm, int wbn)
+{
+ return acm->wb[wbn].use && (acm->wb[wbn].len != 0);
+}
+
+/*
+ * Finish write.
+ */
+static void acm_write_done(struct acm *acm)
+{
+ unsigned long flags;
+ int wbn;
+
+ spin_lock_irqsave(&acm->write_lock, flags);
+ acm->write_ready = 1;
+ wbn = acm->write_current;
+ acm_wb_free(acm, wbn);
+ acm->write_current = (wbn + 1) % ACM_NWB;
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+}
+
+/*
+ * Poke write.
+ */
+static int acm_write_start(struct acm *acm)
+{
+ unsigned long flags;
+ int wbn;
+ struct acm_wb *wb;
+ int rc;
+
+ spin_lock_irqsave(&acm->write_lock, flags);
+ if (!acm->dev) {
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ return -ENODEV;
+ }
+
+ if (!acm->write_ready) {
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ return 0; /* A white lie */
+ }
+
+ wbn = acm->write_current;
+ if (!acm_wb_is_used(acm, wbn)) {
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ return 0;
+ }
+ wb = &acm->wb[wbn];
+
+ acm->write_ready = 0;
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+
+ acm->writeurb->transfer_buffer = wb->buf;
+ acm->writeurb->transfer_dma = wb->dmah;
+ acm->writeurb->transfer_buffer_length = wb->len;
+ acm->writeurb->dev = acm->dev;
+
+ if ((rc = usb_submit_urb(acm->writeurb, GFP_ATOMIC)) < 0) {
+ dbg("usb_submit_urb(write bulk) failed: %d", rc);
+ acm_write_done(acm);
+ }
+ return rc;
+}
+
+/*
* Interrupt handlers for various ACM device responses
*/
@@ -232,17 +340,13 @@
static void acm_write_bulk(struct urb *urb, struct pt_regs *regs)
{
struct acm *acm = (struct acm *)urb->context;
- dbg("Entering acm_write_bulk with status %d\n", urb->status);
- if (!ACM_READY(acm))
- goto out;
-
- if (urb->status)
- dbg("nonzero write bulk status received: %d", urb->status);
+ dbg("Entering acm_write_bulk with status %d\n", urb->status);
- schedule_work(&acm->work);
-out:
- acm->ready_for_write = 1;
+ acm_write_done(acm);
+ acm_write_start(acm);
+ if (ACM_READY(acm))
+ schedule_work(&acm->work);
}
static void acm_softint(void *private)
@@ -339,36 +443,42 @@
{
struct acm *acm = tty->driver_data;
int stat;
+ unsigned long flags;
+ int wbn;
+ struct acm_wb *wb;
+
dbg("Entering acm_tty_write to write %d bytes from %s space,\n", count, from_user ? "user" : "kernel");
if (!ACM_READY(acm))
return -EINVAL;
- if (!acm->ready_for_write)
- return 0;
if (!count)
return 0;
- count = (count > acm->writesize) ? acm->writesize : count;
+ spin_lock_irqsave(&acm->write_lock, flags);
+ if ((wbn = acm_wb_alloc(acm)) < 0) {
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ acm_write_start(acm);
+ return 0;
+ }
+ wb = &acm->wb[wbn];
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ count = (count > acm->writesize) ? acm->writesize : count;
dbg("Get %d bytes from %s space...", count, from_user ? "user" : "kernel");
if (from_user) {
- if (copy_from_user(acm->write_buffer, (void __user *)buf, count))
+ if (copy_from_user(wb->buf, (void __user *)buf, count)) {
+ spin_lock_irqsave(&acm->write_lock, flags);
+ acm_wb_free(acm, wbn);
+ spin_unlock_irqrestore(&acm->write_lock, flags);
return -EFAULT;
+ }
} else
- memcpy(acm->write_buffer, buf, count);
+ memcpy(wb->buf, buf, count);
dbg(" Successfully copied.\n");
+ wb->len = count;
- acm->writeurb->transfer_buffer_length = count;
- acm->writeurb->dev = acm->dev;
-
- acm->ready_for_write = 0;
- stat = usb_submit_urb(acm->writeurb, from_user ? GFP_KERNEL : GFP_ATOMIC);
- if (stat < 0) {
- dbg("usb_submit_urb(write bulk) failed");
- acm->ready_for_write = 1;
+ if ((stat = acm_write_start(acm)) < 0)
return stat;
- }
-
return count;
}
@@ -377,7 +487,11 @@
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return -EINVAL;
- return !acm->ready_for_write ? 0 : acm->writesize;
+ /*
+ * Do not let the line discipline to know that we have a reserve,
+ * or it might get too enthusiastic.
+ */
+ return (acm->write_ready && acm_wb_is_avail(acm)) ? acm->writesize : 0;
}
static int acm_tty_chars_in_buffer(struct tty_struct *tty)
@@ -385,7 +499,10 @@
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return -EINVAL;
- return !acm->ready_for_write ? acm->writeurb->transfer_buffer_length : 0;
+ /*
+ * This is inaccurate (overcounts), but it works.
+ */
+ return (ACM_NWB - acm_wb_is_avail(acm)) * acm->writesize;
}
static void acm_tty_throttle(struct tty_struct *tty)
@@ -516,6 +633,39 @@
* USB probe and disconnect routines.
*/
+/* Little helper: write buffers free */
+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++) {
+ usb_buffer_free(acm->dev, acm->writesize, wb->buf, wb->dmah);
+ }
+}
+
+/* Little helper: write buffers allocate */
+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++) {
+ wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
+ &wb->dmah);
+ if (!wb->buf) {
+ while (i != 0) {
+ --i;
+ --wb;
+ usb_buffer_free(acm->dev, acm->writesize,
+ wb->buf, wb->dmah);
+ }
+ return -ENOMEM;
+ }
+ }
+ return 0;
+}
+
static int acm_probe (struct usb_interface *intf,
const struct usb_device_id *id)
{
@@ -648,9 +798,9 @@
}
memset(acm, 0, sizeof(struct acm));
- ctrlsize = epctrl->wMaxPacketSize;
- readsize = epread->wMaxPacketSize;
- acm->writesize = epwrite->wMaxPacketSize;
+ ctrlsize = (le16_to_cpu(epctrl->wMaxPacketSize) > maxszc)?le16_to_cpu(epctrl->wMaxPacketSize):maxszc;
+ readsize = (le16_to_cpu(epread->wMaxPacketSize) > maxszr)?le16_to_cpu(epread->wMaxPacketSize):maxszr;
+ acm->writesize = (le16_to_cpu(epwrite->wMaxPacketSize) > maxszw)?le16_to_cpu(epwrite->wMaxPacketSize):maxszw;
acm->control = control_interface;
acm->data = data_interface;
acm->minor = minor;
@@ -662,7 +812,8 @@
acm->bh.data = (unsigned long) acm;
INIT_WORK(&acm->work, acm_softint, acm);
spin_lock_init(&acm->throttle_lock);
- acm->ready_for_write = 1;
+ spin_lock_init(&acm->write_lock);
+ acm->write_ready = 1;
buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
if (!buf) {
@@ -678,12 +829,10 @@
}
acm->read_buffer = buf;
- buf = usb_buffer_alloc(usb_dev, acm->writesize, GFP_KERNEL, &acm->write_dma);
- if (!buf) {
+ if (acm_write_buffers_alloc(acm) < 0) {
dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
goto alloc_fail4;
}
- acm->write_buffer = buf;
acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
if (!acm->ctrlurb) {
@@ -712,9 +861,9 @@
acm->readurb->transfer_dma = acm->read_dma;
usb_fill_bulk_urb(acm->writeurb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
- acm->write_buffer, acm->writesize, acm_write_bulk, acm);
+ NULL, acm->writesize, acm_write_bulk, acm);
acm->writeurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;
- acm->writeurb->transfer_dma = acm->write_dma;
+ /* acm->writeurb->transfer_dma = 0; */
dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
@@ -737,7 +886,7 @@
alloc_fail6:
usb_free_urb(acm->ctrlurb);
alloc_fail5:
- usb_buffer_free(usb_dev, acm->writesize, acm->write_buffer, acm->write_dma);
+ acm_write_buffers_free(acm);
alloc_fail4:
usb_buffer_free(usb_dev, readsize, acm->read_buffer, acm->read_dma);
alloc_fail3:
@@ -768,7 +917,7 @@
flush_scheduled_work(); /* wait for acm_softint */
- usb_buffer_free(usb_dev, acm->writesize, acm->write_buffer, acm->write_dma);
+ acm_write_buffers_free(acm);
usb_buffer_free(usb_dev, acm->readsize, acm->read_buffer, acm->read_dma);
usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
@@ -891,4 +1040,9 @@
MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");
-
+module_param(maxszc, ushort,0);
+MODULE_PARM_DESC(maxszc,"User specified USB endpoint control size");
+module_param(maxszr, ushort,0);
+MODULE_PARM_DESC(maxszr,"User specified USB endpoint read size");
+module_param(maxszw, ushort,0);
+MODULE_PARM_DESC(maxszw,"User specified USB endpoint write size");
Only in linux-2.6.9-6.34.EL/drivers/usb/class: cdc-acm.c.orig
diff -u -r linux-2.6.9/drivers/usb/class/cdc-acm.h linux-2.6.9-6.34.EL/drivers/usb/class/cdc-acm.h
--- linux-2.6.9/drivers/usb/class/cdc-acm.h 2004-10-18 17:55:29.000000000 -0400
+++ linux-2.6.9-6.34.EL/drivers/usb/class/cdc-acm.h 2006-06-21 15:42:02.000000000 -0400
@@ -80,14 +80,34 @@
* Internal driver structures.
*/
+/*
+ * The only reason to have several buffers is to accomodate assumptions
+ * 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.
+ */
+#define ACM_NWB 2
+struct acm_wb {
+ unsigned char *buf;
+ dma_addr_t dmah;
+ int len;
+ int use;
+};
+
struct acm {
struct usb_device *dev; /* the corresponding usb device */
struct usb_interface *control; /* control interface */
struct usb_interface *data; /* data interface */
struct tty_struct *tty; /* the corresponding tty */
struct urb *ctrlurb, *readurb, *writeurb; /* urbs */
- u8 *ctrl_buffer, *read_buffer, *write_buffer; /* buffers of urbs */
- dma_addr_t ctrl_dma, read_dma, write_dma; /* dma handles of buffers */
+ u8 *ctrl_buffer, *read_buffer; /* buffers of urbs */
+ dma_addr_t ctrl_dma, read_dma; /* dma handles of buffers */
+ struct acm_wb wb[ACM_NWB];
+ int write_current; /* current write buffer */
+ int write_used; /* number of non-empty write buffers */
+ int write_ready; /* write urb is not running */
+ spinlock_t write_lock;
struct acm_line line; /* line coding (bits, stop, parity) */
struct work_struct work; /* work queue entry for line discipline waking up */
struct tasklet_struct bh; /* rx processing */
@@ -100,7 +120,6 @@
unsigned int minor; /* acm minor number */
unsigned char throttle; /* throttled by tty layer */
unsigned char clocal; /* termios CLOCAL */
- unsigned char ready_for_write; /* write urb can be used */
unsigned char resubmit_to_unthrottle; /* throtteling has disabled the read urb */
unsigned int ctrl_caps; /* control capabilities from the class specific header */
};
diff -u -r linux-2.6.9/drivers/usb/serial/usb-serial.c linux-2.6.9-6.34.EL/drivers/usb/serial/usb-serial.c
--- linux-2.6.9/drivers/usb/serial/usb-serial.c 2004-10-18 17:55:36.000000000 -0400
+++ linux-2.6.9-6.34.EL/drivers/usb/serial/usb-serial.c 2006-06-21 15:53:55.000000000 -0400
@@ -361,6 +361,7 @@
drivers depend on it.
*/
+static ushort maxSize = 0;
static int debug;
static struct usb_serial *serial_table[SERIAL_TTY_MINORS]; /* initially all NULL */
static LIST_HEAD(usb_serial_driver_list);
@@ -1052,7 +1053,7 @@
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
- buffer_size = endpoint->wMaxPacketSize;
+ buffer_size = (le16_to_cpu(endpoint->wMaxPacketSize) > maxSize)?le16_to_cpu(endpoint->wMaxPacketSize):maxSize;
port->bulk_in_endpointAddress = endpoint->bEndpointAddress;
port->bulk_in_buffer = kmalloc (buffer_size, GFP_KERNEL);
if (!port->bulk_in_buffer) {
@@ -1075,7 +1076,7 @@
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
- buffer_size = endpoint->wMaxPacketSize;
+ buffer_size = (le16_to_cpu(endpoint->wMaxPacketSize) > maxSize)?le16_to_cpu(endpoint->wMaxPacketSize):maxSize;
port->bulk_out_size = buffer_size;
port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
port->bulk_out_buffer = kmalloc (buffer_size, GFP_KERNEL);
@@ -1099,7 +1100,7 @@
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
- buffer_size = endpoint->wMaxPacketSize;
+ buffer_size = (le16_to_cpu(endpoint->wMaxPacketSize) > maxSize)?le16_to_cpu(endpoint->wMaxPacketSize):maxSize;
port->interrupt_in_endpointAddress = endpoint->bEndpointAddress;
port->interrupt_in_buffer = kmalloc (buffer_size, GFP_KERNEL);
if (!port->interrupt_in_buffer) {
@@ -1373,3 +1374,5 @@
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
+module_param(maxSize, ushort,0);
+MODULE_PARM_DESC(maxSize,"User specified USB endpoint size");
-------------------------------------------------------------------------
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