On Mon, 25 Jan 2021 04:21:18 +0100, Hui Wang wrote:
This change adds audio jack injection feature through debugfs, with this feature, we could validate alsa userspace changes by injecting plugin or plugout events to the non-phantom audio jacks.
With this change, the sound core will build the folders $debugfs_mount_dir/sound/cardN if SND_DEBUG and DEBUG_FS are enabled. And if users also enable the SND_JACK_INJECTION_DEBUG, the jack injection nodes will be built in the folder cardN like below:
$tree $debugfs_mount_dir/sound $debugfs_mount_dir/sound ├── card0 │ ├── HDMI_DP_pcm_10_Jack │ │ ├── jackin_inject │ │ ├── kctl_id │ │ ├── mask_bits │ │ ├── status │ │ ├── sw_inject_enable │ │ └── type ... │ └── HDMI_DP_pcm_9_Jack │ ├── jackin_inject │ ├── kctl_id │ ├── mask_bits │ ├── status │ ├── sw_inject_enable │ └── type └── card1 ├── HDMI_DP_pcm_5_Jack │ ├── jackin_inject │ ├── kctl_id │ ├── mask_bits │ ├── status │ ├── sw_inject_enable │ └── type ... ├── Headphone_Jack │ ├── jackin_inject │ ├── kctl_id │ ├── mask_bits │ ├── status │ ├── sw_inject_enable │ └── type └── Headset_Mic_Jack ├── jackin_inject ├── kctl_id ├── mask_bits ├── status ├── sw_inject_enable └── type
The nodes kctl_id, mask_bits, status and type are read-only, users could check jack or jack_kctl's information through them.
The nodes sw_inject_enable and jackin_inject are directly used for injection. The sw_inject_enable is read-write, users could check if software injection is enabled or not on this jack, and users could echo 1 or 0 to enable or disable software injection on this jack. Once the injection is enabled, the jack will not change by hardware events anymore, once the injection is disabled, the jack will restore the last reported hardware events to the jack. The jackin_inject is write-only, if the injection is enabled, users could echo 1 or 0 to this node to inject plugin or plugout events to this jack.
For the detailed usage information on these nodes, please refer to Documentation/sound/designs/jack-injection.rst.
Reviewed-by: Takashi Iwai tiwai@suse.de Reviewed-by: Jaroslav Kysela perex@perex.cz Reviewed-by: Kai Vehmanen kai.vehmanen@linux.intel.com Signed-off-by: Hui Wang hui.wang@canonical.com
Some minor nitpicking:
+static int snd_jack_debugfs_add_inject_node(struct snd_jack *jack,
struct snd_jack_kctl *jack_kctl)+{
- char *tname;
- int i;
- tname = kstrdup(jack_kctl->kctl->id.name, GFP_KERNEL);
- if (!tname)
return -ENOMEM;- /* replace the chars which are not suitable for folder's name with _ */
- for (i = 0; i < strlen(tname); i++)
No need to use strlen(), just check the NUL character on tname[i].
--- a/sound/core/sound.c +++ b/sound/core/sound.c @@ -9,6 +9,7 @@ #include <linux/time.h> #include <linux/device.h> #include <linux/module.h> +#include <linux/debugfs.h> #include <sound/core.h> #include <sound/minors.h> #include <sound/info.h> @@ -39,6 +40,9 @@ MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR); int snd_ecards_limit; EXPORT_SYMBOL(snd_ecards_limit);
+struct dentry *sound_debugfs_root; +EXPORT_SYMBOL_GPL(sound_debugfs_root);
I guess this should be wrapped with CONFIG_SND_DEBUG ifdef?
thanks,
Takashi