diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index 08cc2ee5707d..6e443f762de8 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -275,8 +275,8 @@ static inline bool has_tx_length_quirk(struct snd_usb_audio *chip) return chip->quirk_flags & QUIRK_FLAG_TX_LENGTH; } -static void prepare_silent_urb(struct snd_usb_endpoint *ep, - struct snd_urb_ctx *ctx) +static int prepare_silent_urb(struct snd_usb_endpoint *ep, + struct snd_urb_ctx *ctx) { struct urb *urb = ctx->urb; unsigned int offs = 0; @@ -289,28 +289,34 @@ static void prepare_silent_urb(struct snd_usb_endpoint *ep, extra = sizeof(packet_length); for (i = 0; i < ctx->packets; ++i) { - unsigned int offset; - unsigned int length; - int counts; + int length; - counts = snd_usb_endpoint_next_packet_size(ep, ctx, i, 0); - length = counts * ep->stride; /* number of silent bytes */ - offset = offs * ep->stride + extra * i; - urb->iso_frame_desc[i].offset = offset; + length = snd_usb_endpoint_next_packet_size(ep, ctx, i, 0); + if (length < 0) + return length; + length *= ep->stride; /* number of silent bytes */ + if (offs + length + extra > ctx->buffer_size) + break; + urb->iso_frame_desc[i].offset = offs; urb->iso_frame_desc[i].length = length + extra; if (extra) { packet_length = cpu_to_le32(length); - memcpy(urb->transfer_buffer + offset, + memcpy(urb->transfer_buffer + offs, &packet_length, sizeof(packet_length)); + offs += extra; } - memset(urb->transfer_buffer + offset + extra, + memset(urb->transfer_buffer + offs, ep->silence_value, length); - offs += counts; + offs += length; } - urb->number_of_packets = ctx->packets; - urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra; + if (!offs) + return -EPIPE; + + urb->number_of_packets = i; + urb->transfer_buffer_length = offs; ctx->queued = 0; + return 0; } /* @@ -332,8 +338,7 @@ static int prepare_outbound_urb(struct snd_usb_endpoint *ep, if (data_subs && ep->prepare_data_urb) return ep->prepare_data_urb(data_subs, urb, in_stream_lock); /* no data provider, so send silence */ - prepare_silent_urb(ep, ctx); - break; + return prepare_silent_urb(ep, ctx); case SND_USB_ENDPOINT_TYPE_SYNC: if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {