mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 21:24:00 +08:00
[media] em28xx-audio: don't hardcode audio URB calculus
The current code hardcodes the number of audio URBs, the number of packets per URB and the maximum URB size. This is not a good idea, as it: - wastes more bandwidth than necessary, by using a very large number of packets; - those constants are bound to an specific scenario, with a bandwidth of 48 kHz; - don't take the maximum endpoint size into account; - with urb->interval = 1 on xHCI, those constraints cause a "funny" setup: URBs with 64 packets inside, with only 24 bytes total. E. g. a complete waste of space. Change the code to do dynamic URB audio calculus and allocation. For now, use the same constraints as used before this patch, to avoid regressions. A good scenario (tested) seems to use those defines, instead: #define EM28XX_MAX_AUDIO_BUFS 8 #define EM28XX_MIN_AUDIO_PACKETS 2 But let's not do such change here, letting the optimization to happen on latter patches, after more tests. Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
This commit is contained in:
Mauro Carvalho Chehab
parent
439c491c4c
commit
1b3fd2d342
@ -50,6 +50,8 @@ static int debug;
|
||||
module_param(debug, int, 0644);
|
||||
MODULE_PARM_DESC(debug, "activates debug info");
|
||||
|
||||
#define EM28XX_MAX_AUDIO_BUFS 5
|
||||
#define EM28XX_MIN_AUDIO_PACKETS 64
|
||||
#define dprintk(fmt, arg...) do { \
|
||||
if (debug) \
|
||||
printk(KERN_INFO "em28xx-audio %s: " fmt, \
|
||||
@ -63,7 +65,7 @@ static int em28xx_deinit_isoc_audio(struct em28xx *dev)
|
||||
int i;
|
||||
|
||||
dprintk("Stopping isoc\n");
|
||||
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
|
||||
for (i = 0; i < dev->adev.num_urb; i++) {
|
||||
struct urb *urb = dev->adev.urb[i];
|
||||
|
||||
if (!irqs_disabled())
|
||||
@ -168,7 +170,7 @@ static int em28xx_init_audio_isoc(struct em28xx *dev)
|
||||
dprintk("Starting isoc transfers\n");
|
||||
|
||||
/* Start streaming */
|
||||
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
|
||||
for (i = 0; i < dev->adev.num_urb; i++) {
|
||||
memset(dev->adev.transfer_buffer[i], 0x80,
|
||||
dev->adev.urb[i]->transfer_buffer_length);
|
||||
|
||||
@ -598,21 +600,35 @@ static void em28xx_audio_free_urb(struct em28xx *dev)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
|
||||
for (i = 0; i < dev->adev.num_urb; i++) {
|
||||
struct urb *urb = dev->adev.urb[i];
|
||||
|
||||
if (!dev->adev.urb[i])
|
||||
if (!urb)
|
||||
continue;
|
||||
|
||||
usb_free_coherent(dev->udev,
|
||||
urb->transfer_buffer_length,
|
||||
dev->adev.transfer_buffer[i],
|
||||
urb->transfer_dma);
|
||||
if (dev->adev.transfer_buffer[i])
|
||||
usb_free_coherent(dev->udev,
|
||||
urb->transfer_buffer_length,
|
||||
dev->adev.transfer_buffer[i],
|
||||
urb->transfer_dma);
|
||||
|
||||
usb_free_urb(urb);
|
||||
dev->adev.urb[i] = NULL;
|
||||
dev->adev.transfer_buffer[i] = NULL;
|
||||
}
|
||||
kfree(dev->adev.urb);
|
||||
kfree(dev->adev.transfer_buffer);
|
||||
dev->adev.num_urb = 0;
|
||||
}
|
||||
|
||||
/* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
|
||||
static int em28xx_audio_ep_packet_size(struct usb_device *udev,
|
||||
struct usb_endpoint_descriptor *e)
|
||||
{
|
||||
int size = le16_to_cpu(e->wMaxPacketSize);
|
||||
|
||||
if (udev->speed == USB_SPEED_HIGH)
|
||||
return (size & 0x7ff) * (1 + (((size) >> 11) & 0x03));
|
||||
|
||||
return size & 0x7ff;
|
||||
}
|
||||
|
||||
static int em28xx_audio_init(struct em28xx *dev)
|
||||
@ -623,9 +639,8 @@ static int em28xx_audio_init(struct em28xx *dev)
|
||||
struct usb_interface *intf;
|
||||
struct usb_endpoint_descriptor *e, *ep = NULL;
|
||||
static int devnr;
|
||||
int err, i;
|
||||
const int sb_size = EM28XX_NUM_AUDIO_PACKETS *
|
||||
EM28XX_AUDIO_MAX_PACKET_SIZE;
|
||||
int err, i, ep_size, interval, num_urb, npackets;
|
||||
int urb_size, bytes_per_transfer;
|
||||
u8 alt;
|
||||
|
||||
if (!dev->has_alsa_audio || dev->audio_ifnum < 0) {
|
||||
@ -648,6 +663,9 @@ static int em28xx_audio_init(struct em28xx *dev)
|
||||
return err;
|
||||
|
||||
spin_lock_init(&adev->slock);
|
||||
adev->sndcard = card;
|
||||
adev->udev = dev->udev;
|
||||
|
||||
err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
|
||||
if (err < 0) {
|
||||
snd_card_free(card);
|
||||
@ -712,25 +730,92 @@ static int em28xx_audio_init(struct em28xx *dev)
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
/* Alloc URB and transfer buffers */
|
||||
for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
|
||||
ep_size = em28xx_audio_ep_packet_size(dev->udev, ep);
|
||||
interval = 1 << (ep->bInterval - 1);
|
||||
|
||||
em28xx_info("Endpoint 0x%02x %s on intf %d alt %d interval = %d, size %d\n",
|
||||
EM28XX_EP_AUDIO, usb_speed_string(dev->udev->speed),
|
||||
dev->audio_ifnum, alt,
|
||||
interval,
|
||||
ep_size);
|
||||
|
||||
/* Calculate the number and size of URBs to better fit the audio samples */
|
||||
|
||||
/*
|
||||
* Estimate the number of bytes per DMA transfer.
|
||||
*
|
||||
* This is given by the bit rate (for now, only 48000 Hz) multiplied
|
||||
* by 2 channels and 2 bytes/sample divided by the number of microframe
|
||||
* intervals and by the microframe rate (125 us)
|
||||
*/
|
||||
bytes_per_transfer = DIV_ROUND_UP(48000 * 2 * 2, 125 * interval);
|
||||
|
||||
/*
|
||||
* Estimate the number of transfer URBs. Don't let it go past the
|
||||
* maximum number of URBs that is known to be supported by the device.
|
||||
*/
|
||||
num_urb = DIV_ROUND_UP(bytes_per_transfer, ep_size);
|
||||
if (num_urb > EM28XX_MAX_AUDIO_BUFS)
|
||||
num_urb = EM28XX_MAX_AUDIO_BUFS;
|
||||
|
||||
/*
|
||||
* Now that we know the number of bytes per transfer and the number of
|
||||
* URBs, estimate the typical size of an URB, in order to adjust the
|
||||
* minimal number of packets.
|
||||
*/
|
||||
urb_size = bytes_per_transfer / num_urb;
|
||||
|
||||
/*
|
||||
* Now, calculate the amount of audio packets to be filled on each
|
||||
* URB. In order to preserve the old behaviour, use a minimal
|
||||
* threshold for this value.
|
||||
*/
|
||||
npackets = EM28XX_MIN_AUDIO_PACKETS;
|
||||
if (urb_size > ep_size * npackets)
|
||||
npackets = DIV_ROUND_UP(urb_size, ep_size);
|
||||
|
||||
em28xx_info("Number of URBs: %d, with %d packets and %d size",
|
||||
num_urb, npackets, urb_size);
|
||||
|
||||
/* Allocate space to store the number of URBs to be used */
|
||||
|
||||
dev->adev.transfer_buffer = kcalloc(num_urb,
|
||||
sizeof(*dev->adev.transfer_buffer),
|
||||
GFP_ATOMIC);
|
||||
if (!dev->adev.transfer_buffer) {
|
||||
snd_card_free(card);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_ATOMIC);
|
||||
if (!dev->adev.urb) {
|
||||
snd_card_free(card);
|
||||
kfree(dev->adev.transfer_buffer);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
/* Alloc memory for each URB and for each transfer buffer */
|
||||
dev->adev.num_urb = num_urb;
|
||||
for (i = 0; i < num_urb; i++) {
|
||||
struct urb *urb;
|
||||
int j, k;
|
||||
void *buf;
|
||||
|
||||
urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
|
||||
urb = usb_alloc_urb(npackets, GFP_ATOMIC);
|
||||
if (!urb) {
|
||||
em28xx_errdev("usb_alloc_urb failed!\n");
|
||||
em28xx_audio_free_urb(dev);
|
||||
snd_card_free(card);
|
||||
return -ENOMEM;
|
||||
}
|
||||
dev->adev.urb[i] = urb;
|
||||
|
||||
buf = usb_alloc_coherent(dev->udev, sb_size, GFP_ATOMIC,
|
||||
buf = usb_alloc_coherent(dev->udev, npackets * ep_size, GFP_ATOMIC,
|
||||
&urb->transfer_dma);
|
||||
if (!buf) {
|
||||
em28xx_errdev("usb_alloc_coherent failed!\n");
|
||||
em28xx_audio_free_urb(dev);
|
||||
snd_card_free(card);
|
||||
return -ENOMEM;
|
||||
}
|
||||
dev->adev.transfer_buffer[i] = buf;
|
||||
@ -739,23 +824,15 @@ static int em28xx_audio_init(struct em28xx *dev)
|
||||
urb->context = dev;
|
||||
urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
|
||||
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
|
||||
urb->transfer_buffer = dev->adev.transfer_buffer[i];
|
||||
urb->interval = 1 << (ep->bInterval - 1);
|
||||
urb->transfer_buffer = buf;
|
||||
urb->interval = interval;
|
||||
urb->complete = em28xx_audio_isocirq;
|
||||
urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
|
||||
urb->transfer_buffer_length = sb_size;
|
||||
urb->number_of_packets = npackets;
|
||||
urb->transfer_buffer_length = ep_size * npackets;
|
||||
|
||||
if (!i)
|
||||
dprintk("Will use ep 0x%02x on intf %d alt %d interval = %d (rcv isoc pipe: 0x%08x)\n",
|
||||
EM28XX_EP_AUDIO, dev->audio_ifnum, alt,
|
||||
urb->interval,
|
||||
urb->pipe);
|
||||
|
||||
for (j = k = 0; j < EM28XX_NUM_AUDIO_PACKETS;
|
||||
j++, k += EM28XX_AUDIO_MAX_PACKET_SIZE) {
|
||||
for (j = k = 0; j < npackets; j++, k += ep_size) {
|
||||
urb->iso_frame_desc[j].offset = k;
|
||||
urb->iso_frame_desc[j].length =
|
||||
EM28XX_AUDIO_MAX_PACKET_SIZE;
|
||||
urb->iso_frame_desc[j].length = ep_size;
|
||||
}
|
||||
}
|
||||
|
||||
@ -765,8 +842,6 @@ static int em28xx_audio_init(struct em28xx *dev)
|
||||
snd_card_free(card);
|
||||
return err;
|
||||
}
|
||||
adev->sndcard = card;
|
||||
adev->udev = dev->udev;
|
||||
|
||||
em28xx_info("Audio extension successfully initialized\n");
|
||||
return 0;
|
||||
|
||||
@ -481,9 +481,6 @@ struct em28xx_eeprom {
|
||||
u8 string_idx_table;
|
||||
};
|
||||
|
||||
#define EM28XX_AUDIO_BUFS 5
|
||||
#define EM28XX_NUM_AUDIO_PACKETS 64
|
||||
#define EM28XX_AUDIO_MAX_PACKET_SIZE 196 /* static value */
|
||||
#define EM28XX_CAPTURE_STREAM_EN 1
|
||||
|
||||
/* em28xx extensions */
|
||||
@ -498,8 +495,9 @@ struct em28xx_eeprom {
|
||||
|
||||
struct em28xx_audio {
|
||||
char name[50];
|
||||
char *transfer_buffer[EM28XX_AUDIO_BUFS];
|
||||
struct urb *urb[EM28XX_AUDIO_BUFS];
|
||||
unsigned num_urb;
|
||||
char **transfer_buffer;
|
||||
struct urb **urb;
|
||||
struct usb_device *udev;
|
||||
unsigned int capture_transfer_done;
|
||||
struct snd_pcm_substream *capture_pcm_substream;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user