From 966f4163751b456f526a0b0dc8e6a9814df6abd9 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sun, 12 Jan 2014 10:10:34 -0300 Subject: [PATCH] [media] em28xx-audio: split URB initialization code The URB calculus code may eventually be moved to some other place, like at pcm open, if it ends by needing more setups, like working with different bit rates, or different audio latency. So, move it into a separate routine. That also makes the code more readable. No functional changes. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-audio.c | 281 ++++++++++++------------ 1 file changed, 144 insertions(+), 137 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c index f004680219e7..13ba631130cd 100644 --- a/drivers/media/usb/em28xx/em28xx-audio.c +++ b/drivers/media/usb/em28xx/em28xx-audio.c @@ -681,17 +681,154 @@ static int em28xx_audio_ep_packet_size(struct usb_device *udev, return size & 0x7ff; } +static int em28xx_audio_urb_init(struct em28xx *dev) +{ + struct usb_interface *intf; + struct usb_endpoint_descriptor *e, *ep = NULL; + int i, ep_size, interval, num_urb, npackets; + int urb_size, bytes_per_transfer; + u8 alt; + + if (dev->audio_ifnum) + alt = 1; + else + alt = 7; + + intf = usb_ifnum_to_if(dev->udev, dev->audio_ifnum); + + if (intf->num_altsetting <= alt) { + em28xx_errdev("alt %d doesn't exist on interface %d\n", + dev->audio_ifnum, alt); + return -ENODEV; + } + + for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) { + e = &intf->altsetting[alt].endpoint[i].desc; + if (!usb_endpoint_dir_in(e)) + continue; + if (e->bEndpointAddress == EM28XX_EP_AUDIO) { + ep = e; + break; + } + } + + if (!ep) { + em28xx_errdev("Couldn't find an audio endpoint"); + return -ENODEV; + } + + 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) { + return -ENOMEM; + } + + dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_ATOMIC); + if (!dev->adev.urb) { + 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(npackets, GFP_ATOMIC); + if (!urb) { + em28xx_errdev("usb_alloc_urb failed!\n"); + em28xx_audio_free_urb(dev); + return -ENOMEM; + } + dev->adev.urb[i] = urb; + + 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); + return -ENOMEM; + } + dev->adev.transfer_buffer[i] = buf; + + urb->dev = dev->udev; + 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 = buf; + urb->interval = interval; + urb->complete = em28xx_audio_isocirq; + urb->number_of_packets = npackets; + urb->transfer_buffer_length = ep_size * npackets; + + for (j = k = 0; j < npackets; j++, k += ep_size) { + urb->iso_frame_desc[j].offset = k; + urb->iso_frame_desc[j].length = ep_size; + } + } + + return 0; +} + static int em28xx_audio_init(struct em28xx *dev) { struct em28xx_audio *adev = &dev->adev; struct snd_pcm *pcm; struct snd_card *card; - struct usb_interface *intf; - struct usb_endpoint_descriptor *e, *ep = NULL; static int devnr; - int err, i, ep_size, interval, num_urb, npackets; - int urb_size, bytes_per_transfer; - u8 alt; + int err; if (!dev->has_alsa_audio || dev->audio_ifnum < 0) { /* This device does not support the extension (in this case @@ -750,142 +887,12 @@ static int em28xx_audio_init(struct em28xx *dev) em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER); } - if (dev->audio_ifnum) - alt = 1; - else - alt = 7; - - intf = usb_ifnum_to_if(dev->udev, dev->audio_ifnum); - - if (intf->num_altsetting <= alt) { - em28xx_errdev("alt %d doesn't exist on interface %d\n", - dev->audio_ifnum, alt); + err = em28xx_audio_urb_init(dev); + if (err) { snd_card_free(card); return -ENODEV; } - for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) { - e = &intf->altsetting[alt].endpoint[i].desc; - if (!usb_endpoint_dir_in(e)) - continue; - if (e->bEndpointAddress == EM28XX_EP_AUDIO) { - ep = e; - break; - } - } - - if (!ep) { - em28xx_errdev("Couldn't find an audio endpoint"); - snd_card_free(card); - return -ENODEV; - } - - 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(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, 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; - - urb->dev = dev->udev; - 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 = buf; - urb->interval = interval; - urb->complete = em28xx_audio_isocirq; - urb->number_of_packets = npackets; - urb->transfer_buffer_length = ep_size * npackets; - - for (j = k = 0; j < npackets; j++, k += ep_size) { - urb->iso_frame_desc[j].offset = k; - urb->iso_frame_desc[j].length = ep_size; - } - } - err = snd_card_register(card); if (err < 0) { em28xx_audio_free_urb(dev);