Re: [alsa-devel] [alsa-lib][PATCH] test: fix comment about first two fields of TLV data payload

On Tue, 30 Aug 2016 02:21:45 +0200, Takashi Sakamoto wrote:

I misunderstand TLV packet structure (struct snd_ctl_tlv) nests in its payload. But actually, the payload stores different type of data.

This commit corrects a comment in a test program of user control element set including my misunderstanding.

Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp

test/user-ctl-element-set.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/user-ctl-element-set.c b/test/user-ctl-element-set.c index 9b9dc59..f6f050a 100644 --- a/test/user-ctl-element-set.c +++ b/test/user-ctl-element-set.c @@ -418,11 +418,11 @@ static int check_tlv(struct elem_set_trial *trial) int err;

/*

• * See a layout of 'struct snd_ctl_tlv'. I don't know the reason to
  

• * construct this buffer with the same layout. It should be abstracted
  

• * inner userspace library...
  

• * When transferring threshold level information via TLV feature of
  

• * ALSA control interface, the first two fields of packet payload
  

• * consist of data type and data length.
  

  */

• orig[0] = snd_ctl_elem_id_get_numid(trial->id);

• orig[0] = SNDRV_CTL_TLVT_CONTAINER; orig[1] = 6 * sizeof(orig[0]); orig[2] = 'a'; orig[3] = 'b';

The container TLV type expects other TLVs as its content. So the above looks buggy to me...

Takashi