On Thu, 14 Feb 2019 15:35:48 +0100, Pierre-Louis Bossart wrote:
On 2/14/19 3:30 AM, Takashi Iwai wrote:
On Wed, 13 Feb 2019 23:07:22 +0100, Pierre-Louis Bossart wrote:
+int snd_sof_bytes_ext_put(struct snd_kcontrol *kcontrol,
const unsigned int __user *binary_data,unsigned int size)+{
- struct soc_bytes_ext *be =
(struct soc_bytes_ext *)kcontrol->private_value;- struct snd_sof_control *scontrol = be->dobj.private;
- struct snd_sof_dev *sdev = scontrol->sdev;
- struct sof_ipc_ctrl_data *cdata = scontrol->control_data;
- struct snd_ctl_tlv header;
- const struct snd_ctl_tlv __user *tlvd =
(const struct snd_ctl_tlv __user *)binary_data;....
Do we keep supporting TLV-typed ext access in SOF? This seems to be disliked nowadays (since it's a sort of abuse of TLV API), and we agreed for dropping / reducing it.
I started working on a replacement of the TLV w/ the hw-dep and showed it could be introduced fairly easily in the topology with minor changes to the kernel interfaces.
https://github.com/plbossart/sound/commits/proto/hwdep https://github.com/plbossart/alsa-lib/tree/proto/hwdep
However the big open is linking this hw-dep element in DAPM, so that it's handled in the same way as existing controls - specifically that the state is restored on resume. That part looked really invasive and complicated. I was even tempted to consider flipping the approach and define a new control that would expose a hw-dep interface to reuse a lot of the DAPM integration.
In short, we know the TLV is not the path forward, and as soon as we have a replacement we'll switch. For now we have no alternative.
OK, then let's add some comments that this interface is subject to change / drop in future.
thanks,
Takashi