Linux-2.6.12-rc2v2.6.12-rc2

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!

1 files changed, 54 insertions, 0 deletions

diff --git a/drivers/usb/serial/ipaq.h b/drivers/usb/serial/ipaq.h
new file mode 100644
index 000000000000..2b9035918b85
--- /dev/null
+++ b/drivers/usb/serial/ipaq.h
@@ -0,0 +1,54 @@
+/*
+ * 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