linux/drivers/media/dvb/dvb-usb/usb-urb.c

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/* usb-urb.c is part of the DVB USB library.
*
* Copyright (C) 2004-6 Patrick Boettcher (patrick.boettcher@desy.de)
* see dvb-usb-init.c for copyright information.
*
* This file keeps functions for initializing and handling the
* BULK and ISOC USB data transfers in a generic way.
* Can be used for DVB-only and also, that's the plan, for
* Hybrid USB devices (analog and DVB).
*/
#include "dvb-usb-common.h"
/* URB stuff for streaming */
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static void usb_urb_complete(struct urb *urb)
{
struct usb_data_stream *stream = urb->context;
int ptype = usb_pipetype(urb->pipe);
int i;
u8 *b;
deb_uxfer("'%s' urb completed. status: %d, length: %d/%d, pack_num: %d, errors: %d\n",
ptype == PIPE_ISOCHRONOUS ? "isoc" : "bulk",
urb->status,urb->actual_length,urb->transfer_buffer_length,
urb->number_of_packets,urb->error_count);
switch (urb->status) {
case 0: /* success */
case -ETIMEDOUT: /* NAK */
break;
case -ECONNRESET: /* kill */
case -ENOENT:
case -ESHUTDOWN:
return;
default: /* error */
deb_ts("urb completition error %d.\n", urb->status);
break;
}
b = (u8 *) urb->transfer_buffer;
switch (ptype) {
case PIPE_ISOCHRONOUS:
for (i = 0; i < urb->number_of_packets; i++) {
if (urb->iso_frame_desc[i].status != 0)
deb_ts("iso frame descriptor has an error: %d\n",urb->iso_frame_desc[i].status);
else if (urb->iso_frame_desc[i].actual_length > 0)
stream->complete(stream, b + urb->iso_frame_desc[i].offset, urb->iso_frame_desc[i].actual_length);
urb->iso_frame_desc[i].status = 0;
urb->iso_frame_desc[i].actual_length = 0;
}
debug_dump(b,20,deb_uxfer);
break;
case PIPE_BULK:
if (urb->actual_length > 0)
stream->complete(stream, b, urb->actual_length);
break;
default:
err("unkown endpoint type in completition handler.");
return;
}
usb_submit_urb(urb,GFP_ATOMIC);
}
int usb_urb_kill(struct usb_data_stream *stream)
{
int i;
for (i = 0; i < stream->urbs_submitted; i++) {
deb_ts("killing URB no. %d.\n",i);
/* stop the URB */
usb_kill_urb(stream->urb_list[i]);
}
stream->urbs_submitted = 0;
return 0;
}
int usb_urb_submit(struct usb_data_stream *stream)
{
int i,ret;
for (i = 0; i < stream->urbs_initialized; i++) {
deb_ts("submitting URB no. %d\n",i);
if ((ret = usb_submit_urb(stream->urb_list[i],GFP_ATOMIC))) {
err("could not submit URB no. %d - get them all back",i);
usb_urb_kill(stream);
return ret;
}
stream->urbs_submitted++;
}
return 0;
}
static int usb_free_stream_buffers(struct usb_data_stream *stream)
{
if (stream->state & USB_STATE_URB_BUF) {
while (stream->buf_num) {
stream->buf_num--;
deb_mem("freeing buffer %d\n",stream->buf_num);
usb_buffer_free(stream->udev, stream->buf_size,
stream->buf_list[stream->buf_num], stream->dma_addr[stream->buf_num]);
}
}
stream->state &= ~USB_STATE_URB_BUF;
return 0;
}
static int usb_allocate_stream_buffers(struct usb_data_stream *stream, int num, unsigned long size)
{
stream->buf_num = 0;
stream->buf_size = size;
deb_mem("all in all I will use %lu bytes for streaming\n",num*size);
for (stream->buf_num = 0; stream->buf_num < num; stream->buf_num++) {
deb_mem("allocating buffer %d\n",stream->buf_num);
if (( stream->buf_list[stream->buf_num] =
usb_buffer_alloc(stream->udev, size, GFP_ATOMIC,
&stream->dma_addr[stream->buf_num]) ) == NULL) {
deb_mem("not enough memory for urb-buffer allocation.\n");
usb_free_stream_buffers(stream);
return -ENOMEM;
}
deb_mem("buffer %d: %p (dma: %Lu)\n",
stream->buf_num,
stream->buf_list[stream->buf_num], (long long)stream->dma_addr[stream->buf_num]);
memset(stream->buf_list[stream->buf_num],0,size);
stream->state |= USB_STATE_URB_BUF;
}
deb_mem("allocation successful\n");
return 0;
}
static int usb_bulk_urb_init(struct usb_data_stream *stream)
{
int i;
if ((i = usb_allocate_stream_buffers(stream,stream->props.count,
stream->props.u.bulk.buffersize)) < 0)
return i;
/* allocate the URBs */
for (i = 0; i < stream->props.count; i++) {
if ((stream->urb_list[i] = usb_alloc_urb(0,GFP_ATOMIC)) == NULL)
return -ENOMEM;
usb_fill_bulk_urb( stream->urb_list[i], stream->udev,
usb_rcvbulkpipe(stream->udev,stream->props.endpoint),
stream->buf_list[i],
stream->props.u.bulk.buffersize,
usb_urb_complete, stream);
stream->urb_list[i]->transfer_flags = 0;
stream->urbs_initialized++;
}
return 0;
}
static int usb_isoc_urb_init(struct usb_data_stream *stream)
{
int i,j;
if ((i = usb_allocate_stream_buffers(stream,stream->props.count,
stream->props.u.isoc.framesize*stream->props.u.isoc.framesperurb)) < 0)
return i;
/* allocate the URBs */
for (i = 0; i < stream->props.count; i++) {
struct urb *urb;
int frame_offset = 0;
if ((stream->urb_list[i] =
usb_alloc_urb(stream->props.u.isoc.framesperurb,GFP_ATOMIC)) == NULL)
return -ENOMEM;
urb = stream->urb_list[i];
urb->dev = stream->udev;
urb->context = stream;
urb->complete = usb_urb_complete;
urb->pipe = usb_rcvisocpipe(stream->udev,stream->props.endpoint);
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
urb->interval = stream->props.u.isoc.interval;
urb->number_of_packets = stream->props.u.isoc.framesperurb;
urb->transfer_buffer_length = stream->buf_size;
urb->transfer_buffer = stream->buf_list[i];
urb->transfer_dma = stream->dma_addr[i];
for (j = 0; j < stream->props.u.isoc.framesperurb; j++) {
urb->iso_frame_desc[j].offset = frame_offset;
urb->iso_frame_desc[j].length = stream->props.u.isoc.framesize;
frame_offset += stream->props.u.isoc.framesize;
}
stream->urbs_initialized++;
}
return 0;
}
int usb_urb_init(struct usb_data_stream *stream, struct usb_data_stream_properties *props)
{
if (stream == NULL || props == NULL)
return -EINVAL;
memcpy(&stream->props, props, sizeof(*props));
usb_clear_halt(stream->udev,usb_rcvbulkpipe(stream->udev,stream->props.endpoint));
if (stream->complete == NULL) {
err("there is no data callback - this doesn't make sense.");
return -EINVAL;
}
switch (stream->props.type) {
case USB_BULK:
return usb_bulk_urb_init(stream);
case USB_ISOC:
return usb_isoc_urb_init(stream);
default:
err("unkown URB-type for data transfer.");
return -EINVAL;
}
}
int usb_urb_exit(struct usb_data_stream *stream)
{
int i;
usb_urb_kill(stream);
for (i = 0; i < stream->urbs_initialized; i++) {
if (stream->urb_list[i] != NULL) {
deb_mem("freeing URB no. %d.\n",i);
/* free the URBs */
usb_free_urb(stream->urb_list[i]);
}
}
stream->urbs_initialized = 0;
usb_free_stream_buffers(stream);
return 0;
}