android_kernel_xiaomi_sm8350/drivers/media/video/em28xx/em28xx-audio.c
Mauro Carvalho Chehab 83ee87a31d V4L/DVB (8026): Avoids an OOPS if dev struct can't be successfully recovered
On some alsa versions, it seems that snd_pcm_substream_chip(substream)
is returning a NULL pointer. This causes an OOPS, as reported by:

https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.24/+bug/212271
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/212960

This patch avoids the OOPS by not letting and open() succeed.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2008-06-26 15:58:47 -03:00

512 lines
13 KiB
C

/*
* Empiatech em28x1 audio extension
*
* Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
*
* Copyright (C) 2007 Mauro Carvalho Chehab <mchehab@infradead.org>
* - Port to work with the in-kernel driver
* - Several cleanups
*
* This driver is based on my previous au600 usb pstn audio driver
* and inherits all the copyrights
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/init.h>
#include <linux/sound.h>
#include <linux/spinlock.h>
#include <linux/soundcard.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/info.h>
#include <sound/initval.h>
#include <sound/control.h>
#include <media/v4l2-common.h>
#include "em28xx.h"
static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "activates debug info");
#define dprintk(fmt, arg...) do { \
if (debug) \
printk(KERN_INFO "em28xx-audio %s: " fmt, \
__func__, ##arg); \
} while (0)
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static int em28xx_isoc_audio_deinit(struct em28xx *dev)
{
int i;
dprintk("Stopping isoc\n");
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
usb_kill_urb(dev->adev->urb[i]);
usb_free_urb(dev->adev->urb[i]);
dev->adev->urb[i] = NULL;
}
return 0;
}
static void em28xx_audio_isocirq(struct urb *urb)
{
struct em28xx *dev = urb->context;
int i;
unsigned int oldptr;
unsigned long flags;
int period_elapsed = 0;
int status;
unsigned char *cp;
unsigned int stride;
struct snd_pcm_substream *substream;
struct snd_pcm_runtime *runtime;
if (dev->adev->capture_pcm_substream) {
substream = dev->adev->capture_pcm_substream;
runtime = substream->runtime;
stride = runtime->frame_bits >> 3;
for (i = 0; i < urb->number_of_packets; i++) {
int length =
urb->iso_frame_desc[i].actual_length / stride;
cp = (unsigned char *)urb->transfer_buffer +
urb->iso_frame_desc[i].offset;
if (!length)
continue;
spin_lock_irqsave(&dev->adev->slock, flags);
oldptr = dev->adev->hwptr_done_capture;
dev->adev->hwptr_done_capture += length;
if (dev->adev->hwptr_done_capture >=
runtime->buffer_size)
dev->adev->hwptr_done_capture -=
runtime->buffer_size;
dev->adev->capture_transfer_done += length;
if (dev->adev->capture_transfer_done >=
runtime->period_size) {
dev->adev->capture_transfer_done -=
runtime->period_size;
period_elapsed = 1;
}
spin_unlock_irqrestore(&dev->adev->slock, flags);
if (oldptr + length >= runtime->buffer_size) {
unsigned int cnt =
runtime->buffer_size - oldptr - 1;
memcpy(runtime->dma_area + oldptr * stride, cp,
cnt * stride);
memcpy(runtime->dma_area, cp + cnt,
length * stride - cnt * stride);
} else {
memcpy(runtime->dma_area + oldptr * stride, cp,
length * stride);
}
}
if (period_elapsed)
snd_pcm_period_elapsed(substream);
}
urb->status = 0;
if (dev->adev->shutdown)
return;
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status < 0) {
em28xx_errdev("resubmit of audio urb failed (error=%i)\n",
status);
}
return;
}
static int em28xx_init_audio_isoc(struct em28xx *dev)
{
int i, errCode;
const int sb_size = EM28XX_NUM_AUDIO_PACKETS *
EM28XX_AUDIO_MAX_PACKET_SIZE;
dprintk("Starting isoc transfers\n");
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
struct urb *urb;
int j, k;
dev->adev->transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
if (!dev->adev->transfer_buffer[i])
return -ENOMEM;
memset(dev->adev->transfer_buffer[i], 0x80, sb_size);
urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
if (!urb)
return -ENOMEM;
urb->dev = dev->udev;
urb->context = dev;
urb->pipe = usb_rcvisocpipe(dev->udev, 0x83);
urb->transfer_flags = URB_ISO_ASAP;
urb->transfer_buffer = dev->adev->transfer_buffer[i];
urb->interval = 1;
urb->complete = em28xx_audio_isocirq;
urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
urb->transfer_buffer_length = sb_size;
for (j = k = 0; j < EM28XX_NUM_AUDIO_PACKETS;
j++, k += EM28XX_AUDIO_MAX_PACKET_SIZE) {
urb->iso_frame_desc[j].offset = k;
urb->iso_frame_desc[j].length =
EM28XX_AUDIO_MAX_PACKET_SIZE;
}
dev->adev->urb[i] = urb;
}
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
errCode = usb_submit_urb(dev->adev->urb[i], GFP_ATOMIC);
if (errCode) {
em28xx_isoc_audio_deinit(dev);
return errCode;
}
}
return 0;
}
static int em28xx_cmd(struct em28xx *dev, int cmd, int arg)
{
dprintk("%s transfer\n", (dev->adev->capture_stream == STREAM_ON)?
"stop" : "start");
switch (cmd) {
case EM28XX_CAPTURE_STREAM_EN:
if (dev->adev->capture_stream == STREAM_OFF && arg == 1) {
dev->adev->capture_stream = STREAM_ON;
em28xx_init_audio_isoc(dev);
} else if (dev->adev->capture_stream == STREAM_ON && arg == 0) {
dev->adev->capture_stream = STREAM_OFF;
em28xx_isoc_audio_deinit(dev);
} else {
printk(KERN_ERR "An underrun very likely occurred. "
"Ignoring it.\n");
}
return 0;
default:
return -EINVAL;
}
}
static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
size_t size)
{
struct snd_pcm_runtime *runtime = subs->runtime;
dprintk("Alocating vbuffer\n");
if (runtime->dma_area) {
if (runtime->dma_bytes > size)
return 0;
vfree(runtime->dma_area);
}
runtime->dma_area = vmalloc(size);
if (!runtime->dma_area)
return -ENOMEM;
runtime->dma_bytes = size;
return 0;
}
static struct snd_pcm_hardware snd_em28xx_hw_capture = {
.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_MMAP_VALID,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
.rate_min = 48000,
.rate_max = 48000,
.channels_min = 2,
.channels_max = 2,
.buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */
.period_bytes_min = 64, /* 12544/2, */
.period_bytes_max = 12544,
.periods_min = 2,
.periods_max = 98, /* 12544, */
};
static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
{
struct em28xx *dev = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
int ret = 0;
dprintk("opening device and trying to acquire exclusive lock\n");
if (!dev) {
printk(KERN_ERR "BUG: em28xx can't find device struct."
" Can't proceed with open\n");
return -ENODEV;
}
/* Sets volume, mute, etc */
dev->mute = 0;
mutex_lock(&dev->lock);
ret = em28xx_audio_analog_set(dev);
mutex_unlock(&dev->lock);
if (ret < 0)
goto err;
runtime->hw = snd_em28xx_hw_capture;
if (dev->alt == 0 && dev->adev->users == 0) {
int errCode;
dev->alt = 7;
errCode = usb_set_interface(dev->udev, 0, 7);
dprintk("changing alternate number to 7\n");
}
dev->adev->users++;
snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
dev->adev->capture_pcm_substream = substream;
runtime->private_data = dev;
return 0;
err:
printk(KERN_ERR "Error while configuring em28xx mixer\n");
return ret;
}
static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
{
struct em28xx *dev = snd_pcm_substream_chip(substream);
dev->adev->users--;
dprintk("closing device\n");
dev->mute = 1;
mutex_lock(&dev->lock);
em28xx_audio_analog_set(dev);
mutex_unlock(&dev->lock);
if (dev->adev->users == 0 && dev->adev->shutdown == 1) {
dprintk("audio users: %d\n", dev->adev->users);
dprintk("disabling audio stream!\n");
dev->adev->shutdown = 0;
dprintk("released lock\n");
em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, 0);
}
return 0;
}
static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
unsigned int channels, rate, format;
int ret;
dprintk("Setting capture parameters\n");
ret = snd_pcm_alloc_vmalloc_buffer(substream,
params_buffer_bytes(hw_params));
format = params_format(hw_params);
rate = params_rate(hw_params);
channels = params_channels(hw_params);
/* TODO: set up em28xx audio chip to deliver the correct audio format,
current default is 48000hz multiplexed => 96000hz mono
which shouldn't matter since analogue TV only supports mono */
return 0;
}
static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
{
struct em28xx *dev = snd_pcm_substream_chip(substream);
dprintk("Stop capture, if needed\n");
if (dev->adev->capture_stream == STREAM_ON)
em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, 0);
return 0;
}
static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
{
return 0;
}
static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
int cmd)
{
struct em28xx *dev = snd_pcm_substream_chip(substream);
dprintk("Should %s capture\n", (cmd == SNDRV_PCM_TRIGGER_START)?
"start": "stop");
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, 1);
return 0;
case SNDRV_PCM_TRIGGER_STOP:
dev->adev->shutdown = 1;
return 0;
default:
return -EINVAL;
}
}
static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
*substream)
{
struct em28xx *dev;
snd_pcm_uframes_t hwptr_done;
dev = snd_pcm_substream_chip(substream);
hwptr_done = dev->adev->hwptr_done_capture;
return hwptr_done;
}
static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
unsigned long offset)
{
void *pageptr = subs->runtime->dma_area + offset;
return vmalloc_to_page(pageptr);
}
static struct snd_pcm_ops snd_em28xx_pcm_capture = {
.open = snd_em28xx_capture_open,
.close = snd_em28xx_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = snd_em28xx_hw_capture_params,
.hw_free = snd_em28xx_hw_capture_free,
.prepare = snd_em28xx_prepare,
.trigger = snd_em28xx_capture_trigger,
.pointer = snd_em28xx_capture_pointer,
.page = snd_pcm_get_vmalloc_page,
};
static int em28xx_audio_init(struct em28xx *dev)
{
struct em28xx_audio *adev;
struct snd_pcm *pcm;
struct snd_card *card;
static int devnr;
int ret, err;
if (dev->has_audio_class) {
/* This device does not support the extension (in this case
the device is expecting the snd-usb-audio module */
return 0;
}
printk(KERN_INFO "em28xx-audio.c: probing for em28x1 "
"non standard usbaudio\n");
printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus "
"Rechberger\n");
adev = kzalloc(sizeof(*adev), GFP_KERNEL);
if (!adev) {
printk(KERN_ERR "em28xx-audio.c: out of memory\n");
return -1;
}
card = snd_card_new(index[devnr], "Em28xx Audio", THIS_MODULE, 0);
if (card == NULL) {
kfree(adev);
return -ENOMEM;
}
spin_lock_init(&adev->slock);
ret = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
pcm->info_flags = 0;
pcm->private_data = dev;
strcpy(pcm->name, "Empia 28xx Capture");
strcpy(card->driver, "Empia Em28xx Audio");
strcpy(card->shortname, "Em28xx Audio");
strcpy(card->longname, "Empia Em28xx Audio");
err = snd_card_register(card);
if (err < 0) {
snd_card_free(card);
return -ENOMEM;
}
adev->sndcard = card;
adev->udev = dev->udev;
dev->adev = adev;
return 0;
}
static int em28xx_audio_fini(struct em28xx *dev)
{
if (dev == NULL)
return 0;
if (dev->has_audio_class) {
/* This device does not support the extension (in this case
the device is expecting the snd-usb-audio module */
return 0;
}
if (dev->adev) {
snd_card_free(dev->adev->sndcard);
kfree(dev->adev);
dev->adev = NULL;
}
return 0;
}
static struct em28xx_ops audio_ops = {
.id = EM28XX_AUDIO,
.name = "Em28xx Audio Extension",
.init = em28xx_audio_init,
.fini = em28xx_audio_fini,
};
static int __init em28xx_alsa_register(void)
{
return em28xx_register_extension(&audio_ops);
}
static void __exit em28xx_alsa_unregister(void)
{
em28xx_unregister_extension(&audio_ops);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
MODULE_DESCRIPTION("Em28xx Audio driver");
module_init(em28xx_alsa_register);
module_exit(em28xx_alsa_unregister);