Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-19 10:31:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

usb: gadget: f_uac2: fix packet size calculation

Browse Source 
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 <john@metanate.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
John Keeping 2020-01-10 11:28:14 +00:00 committed by Greg Kroah-Hartman
parent 1e056efab9
commit 6b02af3465
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/usb/gadget/function/u_audio.c
View File

@ -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;