On Fri, 02 Sep 2016 13:18:04 +0200, Takashi Sakamoto wrote:
Clemens,
On Aug 31 2016 20:54, Clemens Ladisch wrote:
Takashi Iwai wrote:
TLV has never been and (will never be) an API to handle a generic binary stream.
It would be possible to define something like SNDRV_CTL_TLVT_HWDEP_BLOB or _COEFFICIENTS, or to reserve a range of TLVT values for driver- defined types. (But we cannot change soc-wm-adsp to support only proper TLV data, because this would introduce a regression.)
For our information, I wrote a patch including your idea.
Thanks for your bright comment ;)
Takashi Sakamoto
---- 8< ----
From d1a0eabf1b33fae5de7cedf7aee23778f5dcf46c Mon Sep 17 00:00:00 2001
From: Takashi Sakamoto o-takashi@sakamocchi.jp Date: Fri, 2 Sep 2016 00:12:20 +0900 Subject: [PATCH] ALSA: control: coefficient support
include/uapi/sound/asound.h | 5 +++++ include/uapi/sound/tlv.h | 1 + sound/soc/codecs/wm_adsp.c | 3 ++- sound/soc/soc-ops.c | 37 ++++++++++++++++++++++++++++++++++--- sound/soc/soc-topology.c | 3 ++- 5 files changed, 44 insertions(+), 5 deletions(-)
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index 609cadb..69c0585 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -848,6 +848,11 @@ typedef int __bitwise snd_ctl_elem_iface_t; #define SNDRV_CTL_ELEM_ACCESS_TLV_WRITE (1<<5) /* TLV write is possible */ #define SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE (SNDRV_CTL_ELEM_ACCESS_TLV_READ|SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) #define SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND (1<<6) /* TLV command is possible */ +/*
- Arbitrary data is accepted for coefficients, instead of pure
threshold level
- information.
- */
+#define SNDRV_CTL_ELEM_ACCESS_TLV_COEFF (1<<7) #define SNDRV_CTL_ELEM_ACCESS_INACTIVE (1<<8) /* control does actually nothing, but may be updated */ #define SNDRV_CTL_ELEM_ACCESS_LOCK (1<<9) /* write lock */ #define SNDRV_CTL_ELEM_ACCESS_OWNER (1<<10) /* write lock owner */
The introduction of a new flag is a good idea (although it's better to be named not specifically to coef). Then we can skip such elements to be accessed from alsactl or amixer.
However...
@@ -773,19 +774,49 @@ int snd_soc_bytes_tlv_callback(struct snd_kcontrol *kcontrol, int op_flag, unsigned int size, unsigned int __user *tlv) { struct soc_bytes_ext *params = (void *)kcontrol->private_value;
- unsigned int count = size < params->max ? size : params->max;
unsigned int count;
unsigned int type; int ret = -ENXIO;
/*
* The TLV packet can transfer numerical ID for one control element.* But ALSA control core don't tell it to each implementation of* TLV callback. Here, instead, use the first volatile data to* check access information.*/if (!(kcontrol->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_COEFF))
return -ENXIO;/* The data should be constructed according to TLV protocol. */
if (copy_from_user(&type, tlv, sizeof(unsigned int)))
return -EFAULT;/* The type should be an arbitrary data. */
if (type != SNDRV_CTL_TLVT_COEFF)
return -ENXIO;
This breaks the already existing application and is a regression, as Clemens mentioned. This should have been forced from the beginning, but it's too late to put now. So, it's likely no-go.
But, the addition of the flag is helpful alone. Could you concentrate on that and resubmit?
thanks,
Takashi