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Diffstat (limited to 'sound/usb/endpoint.c')
-rw-r--r--sound/usb/endpoint.c92
1 files changed, 69 insertions, 23 deletions
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index e6f71894ecdc..7b1cb365ffab 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -183,13 +183,53 @@ static void retire_inbound_urb(struct snd_usb_endpoint *ep,
ep->retire_data_urb(ep->data_subs, urb);
}
+static void prepare_silent_urb(struct snd_usb_endpoint *ep,
+ struct snd_urb_ctx *ctx)
+{
+ struct urb *urb = ctx->urb;
+ unsigned int offs = 0;
+ unsigned int extra = 0;
+ __le32 packet_length;
+ int i;
+
+ /* For tx_length_quirk, put packet length at start of packet */
+ if (ep->chip->tx_length_quirk)
+ extra = sizeof(packet_length);
+
+ for (i = 0; i < ctx->packets; ++i) {
+ unsigned int offset;
+ unsigned int length;
+ int counts;
+
+ if (ctx->packet_size[i])
+ counts = ctx->packet_size[i];
+ else
+ counts = snd_usb_endpoint_next_packet_size(ep);
+
+ length = counts * ep->stride; /* number of silent bytes */
+ offset = offs * ep->stride + extra * i;
+ urb->iso_frame_desc[i].offset = offset;
+ urb->iso_frame_desc[i].length = length + extra;
+ if (extra) {
+ packet_length = cpu_to_le32(length);
+ memcpy(urb->transfer_buffer + offset,
+ &packet_length, sizeof(packet_length));
+ }
+ memset(urb->transfer_buffer + offset + extra,
+ ep->silence_value, length);
+ offs += counts;
+ }
+
+ urb->number_of_packets = ctx->packets;
+ urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
+}
+
/*
* Prepare a PLAYBACK urb for submission to the bus.
*/
static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *ctx)
{
- int i;
struct urb *urb = ctx->urb;
unsigned char *cp = urb->transfer_buffer;
@@ -201,24 +241,7 @@ static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
ep->prepare_data_urb(ep->data_subs, urb);
} else {
/* no data provider, so send silence */
- unsigned int offs = 0;
- for (i = 0; i < ctx->packets; ++i) {
- int counts;
-
- if (ctx->packet_size[i])
- counts = ctx->packet_size[i];
- else
- counts = snd_usb_endpoint_next_packet_size(ep);
-
- urb->iso_frame_desc[i].offset = offs * ep->stride;
- urb->iso_frame_desc[i].length = counts * ep->stride;
- offs += counts;
- }
-
- urb->number_of_packets = ctx->packets;
- urb->transfer_buffer_length = offs * ep->stride;
- memset(urb->transfer_buffer, ep->silence_value,
- offs * ep->stride);
+ prepare_silent_urb(ep, ctx);
}
break;
@@ -594,6 +617,8 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep,
unsigned int max_packs_per_period, urbs_per_period, urb_packs;
unsigned int max_urbs, i;
int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
+ int tx_length_quirk = (ep->chip->tx_length_quirk &&
+ usb_pipeout(ep->pipe));
if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
/*
@@ -610,13 +635,34 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep,
/* assume max. frequency is 25% higher than nominal */
ep->freqmax = ep->freqn + (ep->freqn >> 2);
- maxsize = ((ep->freqmax + 0xffff) * (frame_bits >> 3))
- >> (16 - ep->datainterval);
+ /* Round up freqmax to nearest integer in order to calculate maximum
+ * packet size, which must represent a whole number of frames.
+ * This is accomplished by adding 0x0.ffff before converting the
+ * Q16.16 format into integer.
+ * In order to accurately calculate the maximum packet size when
+ * the data interval is more than 1 (i.e. ep->datainterval > 0),
+ * multiply by the data interval prior to rounding. For instance,
+ * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
+ * frames with a data interval of 1, but 11 (10.25) frames with a
+ * data interval of 2.
+ * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
+ * maximum datainterval value of 3, at USB full speed, higher for
+ * USB high speed, noting that ep->freqmax is in units of
+ * frames per packet in Q16.16 format.)
+ */
+ maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
+ (frame_bits >> 3);
+ if (tx_length_quirk)
+ maxsize += sizeof(__le32); /* Space for length descriptor */
/* but wMaxPacketSize might reduce this */
if (ep->maxpacksize && ep->maxpacksize < maxsize) {
/* whatever fits into a max. size packet */
- maxsize = ep->maxpacksize;
- ep->freqmax = (maxsize / (frame_bits >> 3))
+ unsigned int data_maxsize = maxsize = ep->maxpacksize;
+
+ if (tx_length_quirk)
+ /* Need to remove the length descriptor to calc freq */
+ data_maxsize -= sizeof(__le32);
+ ep->freqmax = (data_maxsize / (frame_bits >> 3))
<< (16 - ep->datainterval);
}