USB: increase cdc-acm write throughput
the following patch uses 16 write urbs and a writsize of wMaxPacketSize
* 20. With this patch I get the maximum througput from my linux system
with 20MB/sec read and 15 MB/sec write (full speed 1 MB/sec both)
I also deleted the flag URB_NO_FSBR for the writeurbs, because this
makes my full speed devices significant slower.
Signed-off-by: David Engraf <david.engraf@netcom.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 1ded83b..d9b4081 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -31,6 +31,7 @@
* v0.23 - use softirq for rx processing, as needed by tty layer
* v0.24 - change probe method to evaluate CDC union descriptor
* v0.25 - downstream tasks paralelized to maximize throughput
+ * v0.26 - multiple write urbs, writesize increased
*/
/*
@@ -72,7 +73,7 @@
/*
* Version Information
*/
-#define DRIVER_VERSION "v0.25"
+#define DRIVER_VERSION "v0.26"
#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek"
#define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
@@ -118,7 +119,7 @@
int i, wbn;
struct acm_wb *wb;
- wbn = acm->write_current;
+ wbn = 0;
i = 0;
for (;;) {
wb = &acm->wb[wbn];
@@ -132,11 +133,6 @@
}
}
-static void acm_wb_free(struct acm *acm, int wbn)
-{
- acm->wb[wbn].use = 0;
-}
-
static int acm_wb_is_avail(struct acm *acm)
{
int i, n;
@@ -156,26 +152,22 @@
/*
* Finish write.
*/
-static void acm_write_done(struct acm *acm)
+static void acm_write_done(struct acm *acm, struct acm_wb *wb)
{
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_NW;
+ wb->use = 0;
spin_unlock_irqrestore(&acm->write_lock, flags);
}
/*
* Poke write.
*/
-static int acm_write_start(struct acm *acm)
+static int acm_write_start(struct acm *acm, int wbn)
{
unsigned long flags;
- int wbn;
struct acm_wb *wb;
int rc;
@@ -190,24 +182,24 @@
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;
+ if(acm_wb_is_avail(acm) <= 1)
+ 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;
+ wb->urb->transfer_buffer = wb->buf;
+ wb->urb->transfer_dma = wb->dmah;
+ wb->urb->transfer_buffer_length = wb->len;
+ wb->urb->dev = acm->dev;
- if ((rc = usb_submit_urb(acm->writeurb, GFP_ATOMIC)) < 0) {
+ if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
dbg("usb_submit_urb(write bulk) failed: %d", rc);
- acm_write_done(acm);
+ acm_write_done(acm, wb);
}
return rc;
}
@@ -450,12 +442,13 @@
/* data interface wrote those outgoing bytes */
static void acm_write_bulk(struct urb *urb)
{
- struct acm *acm = (struct acm *)urb->context;
+ struct acm *acm;
+ struct acm_wb *wb = (struct acm_wb *)urb->context;
dbg("Entering acm_write_bulk with status %d", urb->status);
- acm_write_done(acm);
- acm_write_start(acm);
+ acm = wb->instance;
+ acm_write_done(acm, wb);
if (ACM_READY(acm))
schedule_work(&acm->work);
}
@@ -557,7 +550,8 @@
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_NW; i++)
+ usb_free_urb(acm->wb[i].urb);
for (i = 0; i < nr; i++)
usb_free_urb(acm->ru[i].urb);
kfree(acm->country_codes);
@@ -578,7 +572,8 @@
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_NW; i++)
+ usb_kill_urb(acm->wb[i].urb);
for (i = 0; i < nr; i++)
usb_kill_urb(acm->ru[i].urb);
usb_autopm_put_interface(acm->control);
@@ -606,7 +601,6 @@
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];
@@ -617,7 +611,7 @@
wb->len = count;
spin_unlock_irqrestore(&acm->write_lock, flags);
- if ((stat = acm_write_start(acm)) < 0)
+ if ((stat = acm_write_start(acm, wbn)) < 0)
return stat;
return count;
}
@@ -977,7 +971,7 @@
ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
readsize = le16_to_cpu(epread->wMaxPacketSize)* ( quirks == SINGLE_RX_URB ? 1 : 2);
- acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize);
+ acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize) * 20;
acm->control = control_interface;
acm->data = data_interface;
acm->minor = minor;
@@ -1032,10 +1026,19 @@
goto alloc_fail7;
}
}
- acm->writeurb = usb_alloc_urb(0, GFP_KERNEL);
- if (!acm->writeurb) {
- dev_dbg(&intf->dev, "out of memory (writeurb kmalloc)\n");
- goto alloc_fail7;
+ for(i = 0; i < ACM_NW; i++)
+ {
+ struct acm_wb *snd = &(acm->wb[i]);
+
+ if (!(snd->urb = usb_alloc_urb(0, GFP_KERNEL))) {
+ dev_dbg(&intf->dev, "out of memory (write urbs usb_alloc_urb)");
+ goto alloc_fail7;
+ }
+
+ usb_fill_bulk_urb(snd->urb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
+ NULL, acm->writesize, acm_write_bulk, snd);
+ snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ snd->instance = acm;
}
usb_set_intfdata (intf, acm);
@@ -1071,10 +1074,6 @@
acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
acm->ctrlurb->transfer_dma = acm->ctrl_dma;
- usb_fill_bulk_urb(acm->writeurb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
- NULL, acm->writesize, acm_write_bulk, acm);
- acm->writeurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;
-
dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
acm_set_control(acm, acm->ctrlout);
@@ -1092,7 +1091,8 @@
return 0;
alloc_fail8:
- usb_free_urb(acm->writeurb);
+ for (i = 0; i < ACM_NW; i++)
+ usb_free_urb(acm->wb[i].urb);
alloc_fail7:
for (i = 0; i < num_rx_buf; i++)
usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
@@ -1116,7 +1116,8 @@
tasklet_disable(&acm->urb_task);
usb_kill_urb(acm->ctrlurb);
- usb_kill_urb(acm->writeurb);
+ for(i = 0; i < ACM_NW; i++)
+ usb_kill_urb(acm->wb[i].urb);
for (i = 0; i < acm->rx_buflimit; i++)
usb_kill_urb(acm->ru[i].urb);