From d2849fa59d79dea7a6deeef13cc3efaafab3bf63 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 10 Jan 2014 05:43:09 -0300 Subject: [PATCH] [media] em28xx-audio: use bInterval on em28xx-audio Just filling urb->interval with 1 is wrong, and causes a different behaviour with xHCI. With EHCI, the URB size is typically 192 bytes. However, as xHCI specifies intervals in microframes, the URB size becomes too short (24 bytes). With this patch, the interval will be properly initialized, and the device will behave the same if connected into a xHCI or an EHCI device port. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-audio.c | 39 ++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c index 30ee389a07f..8e6f0487342 100644 --- a/drivers/media/usb/em28xx/em28xx-audio.c +++ b/drivers/media/usb/em28xx/em28xx-audio.c @@ -620,10 +620,13 @@ 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; const int sb_size = EM28XX_NUM_AUDIO_PACKETS * EM28XX_AUDIO_MAX_PACKET_SIZE; + u8 alt; if (!dev->has_alsa_audio || dev->audio_ifnum < 0) { /* This device does not support the extension (in this case @@ -679,6 +682,34 @@ 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); + 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; + } + /* Alloc URB and transfer buffers */ for (i = 0; i < EM28XX_AUDIO_BUFS; i++) { struct urb *urb; @@ -707,11 +738,17 @@ static int em28xx_audio_init(struct em28xx *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; + urb->interval = 1 << (ep->bInterval - 1); urb->complete = em28xx_audio_isocirq; urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS; urb->transfer_buffer_length = sb_size; + 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) { urb->iso_frame_desc[j].offset = k; -- 2.41.0