From 6b02af3465ee11b63a938b13bddbf7ecd92860f3 Mon Sep 17 00:00:00 2001 From: John Keeping Date: Fri, 10 Jan 2020 11:28:14 +0000 Subject: [PATCH] usb: gadget: f_uac2: fix packet size calculation The packet size for USB audio must always be a multiple of the frame size, otherwise we are transmitting a partial frame which omits some channels (and these end up at the wrong offset in the next packet). Furthermore, it breaks the residue handling such that we end up trying to send a packet exceeding the maximum packet size for the endpoint. Signed-off-by: John Keeping Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/u_audio.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c index cf4f2358889b5..6d956f190f5ac 100644 --- a/drivers/usb/gadget/function/u_audio.c +++ b/drivers/usb/gadget/function/u_audio.c @@ -407,7 +407,7 @@ int u_audio_start_playback(struct g_audio *audio_dev) struct usb_ep *ep; struct uac_rtd_params *prm; struct uac_params *params = &audio_dev->params; - unsigned int factor, rate; + unsigned int factor; const struct usb_endpoint_descriptor *ep_desc; int req_len, i; @@ -426,13 +426,15 @@ int u_audio_start_playback(struct g_audio *audio_dev) /* pre-compute some values for iso_complete() */ uac->p_framesize = params->p_ssize * num_channels(params->p_chmask); - rate = params->p_srate * uac->p_framesize; uac->p_interval = factor / (1 << (ep_desc->bInterval - 1)); - uac->p_pktsize = min_t(unsigned int, rate / uac->p_interval, + uac->p_pktsize = min_t(unsigned int, + uac->p_framesize * + (params->p_srate / uac->p_interval), prm->max_psize); if (uac->p_pktsize < prm->max_psize) - uac->p_pktsize_residue = rate % uac->p_interval; + uac->p_pktsize_residue = uac->p_framesize * + (params->p_srate % uac->p_interval); else uac->p_pktsize_residue = 0; -- 2.30.2