On Fri, 01 Oct 2021 12:44:17 +0200,
Colin King wrote:
>
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Variable sample_accum is not being intialized and then has
> ep->sample_rem added to it, leading to a bogus value. One solution
> is to initialize it to zero at declaration time, but it is probably
> best to just assign it to ep->sample_rem on first use.
>
> Addresses-Coveriry: ("Uninitialized scalar variable")
> Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Thanks for the patch, but it's no right fix. The Fixes tag points to
a wrong commit, it was d215f63d49da9a8803af3e81acd6cad743686573
ALSA: usb-audio: Check available frames for the next packet size
And sample_accum has to be initialized from ep->sample_accum instead.
I'll post the proper fix.
Takashi
> ---
> sound/usb/endpoint.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
> index 42c0d2db8ba8..c6a33732db3f 100644
> --- a/sound/usb/endpoint.c
> +++ b/sound/usb/endpoint.c
> @@ -182,7 +182,7 @@ static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail)
> if (ep->fill_max)
> return ep->maxframesize;
>
> - sample_accum += ep->sample_rem;
> + sample_accum = ep->sample_rem;
> if (sample_accum >= ep->pps) {
> sample_accum -= ep->pps;
> ret = ep->packsize[1];
> --
> 2.32.0
>
