mirror of
https://github.com/torvalds/linux.git
synced 2024-11-05 19:41:54 +00:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
55 lines
1.6 KiB
C
55 lines
1.6 KiB
C
/*
|
|
* USB Compaq iPAQ driver
|
|
*
|
|
* Copyright (C) 2001 - 2002
|
|
* Ganesh Varadarajan <ganesh@veritas.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
*/
|
|
|
|
#ifndef __LINUX_USB_SERIAL_IPAQ_H
|
|
#define __LINUX_USB_SERIAL_IPAQ_H
|
|
|
|
/*
|
|
* Since we can't queue our bulk write urbs (don't know why - it just
|
|
* doesn't work), we can send down only one write urb at a time. The simplistic
|
|
* approach taken by the generic usbserial driver will work, but it's not good
|
|
* for performance. Therefore, we buffer upto URBDATA_QUEUE_MAX bytes of write
|
|
* requests coming from the line discipline. This is done by chaining them
|
|
* in lists of struct ipaq_packet, each packet holding a maximum of
|
|
* PACKET_SIZE bytes.
|
|
*
|
|
* ipaq_write() can be called from bottom half context; hence we can't
|
|
* allocate memory for packets there. So we initialize a pool of packets at
|
|
* the first open and maintain a freelist.
|
|
*
|
|
* The value of PACKET_SIZE was empirically determined by
|
|
* checking the maximum write sizes sent down by the ppp ldisc.
|
|
* URBDATA_QUEUE_MAX is set to 64K, which is the maximum TCP window size.
|
|
*/
|
|
|
|
struct ipaq_packet {
|
|
char *data;
|
|
size_t len;
|
|
size_t written;
|
|
struct list_head list;
|
|
};
|
|
|
|
struct ipaq_private {
|
|
int active;
|
|
int queue_len;
|
|
int free_len;
|
|
struct list_head queue;
|
|
struct list_head freelist;
|
|
};
|
|
|
|
#define URBDATA_SIZE 4096
|
|
#define URBDATA_QUEUE_MAX (64 * 1024)
|
|
#define PACKET_SIZE 256
|
|
|
|
#endif
|