On Aug 30 2016 14:32, Takashi Iwai wrote:
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@xxxxxxxxxxxxx>
---
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...
This is a test program just to serve to myself. So I hope this degree of
roughness is allowed...
Or could you please construct valid TLV array here? I don't exactly know
the way to do it, because I've never touched better documentation about
whole design of TLV payload data.
Regards
Takashi Sakamoto
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