From d83b405383c965498923f3561c3321e2b5df5727 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 6 Nov 2011 19:06:37 +0100 Subject: USB: serial: add support for multiple read urbs Add support for multiple read urbs to generic read implementation. Use a static array of two read urbs for now which is enough to get a 50% throughput increase in one test setup. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/generic.c | 83 +++++++++++++++++++++++++++++++++----------- 1 file changed, 62 insertions(+), 21 deletions(-) (limited to 'drivers/usb/serial/generic.c') diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index e4db5ad2bc5..f7403576f99 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -1,7 +1,7 @@ /* * USB Serial Converter Generic functions * - * Copyright (C) 2010 Johan Hovold (jhovold@gmail.com) + * Copyright (C) 2010 - 2011 Johan Hovold (jhovold@gmail.com) * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com) * * This program is free software; you can redistribute it and/or @@ -132,7 +132,7 @@ int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port /* if we have a bulk endpoint, start reading from it */ if (port->bulk_in_size) - result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL); + result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); return result; } @@ -157,8 +157,10 @@ static void generic_cleanup(struct usb_serial_port *port) kfifo_reset_out(&port->write_fifo); spin_unlock_irqrestore(&port->lock, flags); } - if (port->bulk_in_size) - usb_kill_urb(port->read_urb); + if (port->bulk_in_size) { + for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) + usb_kill_urb(port->read_urbs[i]); + } } } @@ -308,19 +310,52 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) return chars; } -int usb_serial_generic_submit_read_urb(struct usb_serial_port *port, +static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port, + int index, gfp_t mem_flags) +{ + int res; + + if (!test_and_clear_bit(index, &port->read_urbs_free)) + return 0; + + dbg("%s - port %d, urb %d\n", __func__, port->number, index); + + res = usb_submit_urb(port->read_urbs[index], mem_flags); + if (res) { + if (res != -EPERM) { + dev_err(&port->dev, + "%s - usb_submit_urb failed: %d\n", + __func__, res); + } + set_bit(index, &port->read_urbs_free); + return res; + } + + return 0; +} + +int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, gfp_t mem_flags) { - int result; + int res; + int i; - result = usb_submit_urb(port->read_urb, mem_flags); - if (result && result != -EPERM) { - dev_err(&port->dev, "%s - error submitting urb: %d\n", - __func__, result); + dbg("%s - port %d", __func__, port->number); + + for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) { + res = usb_serial_generic_submit_read_urb(port, i, mem_flags); + if (res) + goto err; } - return result; + + return 0; +err: + for (; i >= 0; --i) + usb_kill_urb(port->read_urbs[i]); + + return res; } -EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb); +EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs); void usb_serial_generic_process_read_urb(struct urb *urb) { @@ -356,14 +391,19 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) { struct usb_serial_port *port = urb->context; unsigned char *data = urb->transfer_buffer; - int status = urb->status; unsigned long flags; + int i; - dbg("%s - port %d", __func__, port->number); + for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) { + if (urb == port->read_urbs[i]) + break; + } + set_bit(i, &port->read_urbs_free); - if (unlikely(status != 0)) { - dbg("%s - nonzero read bulk status received: %d", - __func__, status); + dbg("%s - port %d, urb %d, len %d\n", __func__, port->number, i, + urb->actual_length); + if (urb->status) { + dbg("%s - non-zero urb status: %d\n", __func__, urb->status); return; } @@ -376,7 +416,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) port->throttled = port->throttle_req; if (!port->throttled) { spin_unlock_irqrestore(&port->lock, flags); - usb_serial_generic_submit_read_urb(port, GFP_ATOMIC); + usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC); } else spin_unlock_irqrestore(&port->lock, flags); } @@ -443,7 +483,7 @@ void usb_serial_generic_unthrottle(struct tty_struct *tty) spin_unlock_irq(&port->lock); if (was_throttled) - usb_serial_generic_submit_read_urb(port, GFP_KERNEL); + usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); } EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle); @@ -509,8 +549,9 @@ int usb_serial_generic_resume(struct usb_serial *serial) if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) continue; - if (port->read_urb) { - r = usb_submit_urb(port->read_urb, GFP_NOIO); + if (port->bulk_in_size) { + r = usb_serial_generic_submit_read_urbs(port, + GFP_NOIO); if (r < 0) c++; } -- cgit v1.2.3