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authorElina Pasheva <epasheva@sierrawireless.com>2009-04-29 10:26:46 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2009-06-15 21:44:45 -0700
commit40d2ff32f102e69d482480265ec60ffb86b028de (patch)
treee296e28a1139c3f785328e043c112332764ca584 /drivers/usb/serial
parente05b8e6e1066e7583dbb6b00407508797b737995 (diff)
USB: serial: sierra driver write path improvements
- Updated Copyright notice with new authors names - Version number set to 1.3.6 - Added a MAX_TRANSFER constant following Greg Kroah-Hartman's recommended setting of PAGE_SIZE-512 for USB transfer buffers and modified accordingly sierra_write() function. Signed-off-by: Elina Pasheva <epasheva@sierrawireless.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/serial')
-rw-r--r--drivers/usb/serial/sierra.c52
1 files changed, 35 insertions, 17 deletions
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index f75688416b6..27f41f95aef 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -1,7 +1,10 @@
/*
USB Driver for Sierra Wireless
- Copyright (C) 2006, 2007, 2008 Kevin Lloyd <klloyd@sierrawireless.com>
+ Copyright (C) 2006, 2007, 2008 Kevin Lloyd <klloyd@sierrawireless.com>,
+
+ Copyright (C) 2008, 2009 Elina Pasheva, Matthew Safar, Rory Filer
+ <linux@sierrawireless.com>
IMPORTANT DISCLAIMER: This driver is not commercially supported by
Sierra Wireless. Use at your own risk.
@@ -14,8 +17,8 @@
Whom based his on the Keyspan driver by Hugh Blemings <hugh@blemings.org>
*/
-#define DRIVER_VERSION "v.1.3.5"
-#define DRIVER_AUTHOR "Kevin Lloyd <klloyd@sierrawireless.com>"
+#define DRIVER_VERSION "v.1.3.6"
+#define DRIVER_AUTHOR "Kevin Lloyd, Elina Pasheva, Matthew Safar, Rory Filer"
#define DRIVER_DESC "USB Driver for Sierra Wireless USB modems"
#include <linux/kernel.h>
@@ -34,6 +37,11 @@
#define N_OUT_URB 64
#define IN_BUFLEN 4096
+#define MAX_TRANSFER (PAGE_SIZE - 512)
+/* MAX_TRANSFER is chosen so that the VM is not stressed by
+ allocations > PAGE_SIZE and the number of packets in a page
+ is an integer 512 is the largest possible packet on EHCI */
+
static int debug;
static int nmea;
@@ -419,50 +427,58 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
unsigned long flags;
unsigned char *buffer;
struct urb *urb;
- int status;
+ size_t writesize = min((size_t)count, (size_t)MAX_TRANSFER);
+ int retval = 0;
+
+ /* verify that we actually have some data to write */
+ if (count == 0)
+ return 0;
portdata = usb_get_serial_port_data(port);
- dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
+ dev_dbg(&port->dev, "%s: write (%d bytes)\n", __func__, writesize);
spin_lock_irqsave(&portdata->lock, flags);
+ dev_dbg(&port->dev, "%s - outstanding_urbs: %d\n", __func__,
+ portdata->outstanding_urbs);
if (portdata->outstanding_urbs > N_OUT_URB) {
spin_unlock_irqrestore(&portdata->lock, flags);
dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
return 0;
}
portdata->outstanding_urbs++;
+ dev_dbg(&port->dev, "%s - 1, outstanding_urbs: %d\n", __func__,
+ portdata->outstanding_urbs);
spin_unlock_irqrestore(&portdata->lock, flags);
- buffer = kmalloc(count, GFP_ATOMIC);
+ buffer = kmalloc(writesize, GFP_ATOMIC);
if (!buffer) {
dev_err(&port->dev, "out of memory\n");
- count = -ENOMEM;
+ retval = -ENOMEM;
goto error_no_buffer;
}
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {
dev_err(&port->dev, "no more free urbs\n");
- count = -ENOMEM;
+ retval = -ENOMEM;
goto error_no_urb;
}
- memcpy(buffer, buf, count);
+ memcpy(buffer, buf, writesize);
- usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
+ usb_serial_debug_data(debug, &port->dev, __func__, writesize, buffer);
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev,
port->bulk_out_endpointAddress),
- buffer, count, sierra_outdat_callback, port);
+ buffer, writesize, sierra_outdat_callback, port);
/* send it down the pipe */
- status = usb_submit_urb(urb, GFP_ATOMIC);
- if (status) {
+ retval = usb_submit_urb(urb, GFP_ATOMIC);
+ if (retval) {
dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed "
- "with status = %d\n", __func__, status);
- count = status;
+ "with status = %d\n", __func__, retval);
goto error;
}
@@ -470,7 +486,7 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
* really free it when it is finished with it */
usb_free_urb(urb);
- return count;
+ return writesize;
error:
usb_free_urb(urb);
error_no_urb:
@@ -478,8 +494,10 @@ error_no_urb:
error_no_buffer:
spin_lock_irqsave(&portdata->lock, flags);
--portdata->outstanding_urbs;
+ dev_dbg(&port->dev, "%s - 2. outstanding_urbs: %d\n", __func__,
+ portdata->outstanding_urbs);
spin_unlock_irqrestore(&portdata->lock, flags);
- return count;
+ return retval;
}
static void sierra_indat_callback(struct urb *urb)