[alsa-devel] [PATCH] ASoC: snd-sof-pci - add model parameter and pass it to HDA codec driver

[Pierre-Louis Bossart]

On 12/3/19 10:19 AM, Jaroslav Kysela wrote:
> It may be useful to pass the specific model to the generic HDA codec
> routines like the legacy HDA driver (snd-hda-intel) allows.
> The model name "sofbus" is tricky anyway.

Humm, I must admit I have never looked at this for the legacy driver, 
and I am a bit confused on what this would be used for?
The legacy driver uses codec->modelname but I can't figure out this part 
in hda_codec.c

if (codec->bus->modelname) {
	codec->modelname = kstrdup(codec->bus->modelname, GFP_KERNEL);

In theory there can be multiple codecs per bus (with different SDIs) so 
using the bus->modelname for the codec->modelname looks odd.
Is there an example of this being used for my education?

Also it'd make more sense to me to have this parameter in an 
intel-specific module, not the top level PCI one?

> 
> Signed-off-by: Jaroslav Kysela <perex at perex.cz>
> Cc: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> Cc: Mark Brown <broonie at kernel.org>
> ---
>   include/sound/sof.h         | 1 +
>   sound/soc/sof/intel/hda.c   | 2 +-
>   sound/soc/sof/sof-pci-dev.c | 5 +++++
>   3 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/include/sound/sof.h b/include/sound/sof.h
> index 479101736ee0..a62686baa95d 100644
> --- a/include/sound/sof.h
> +++ b/include/sound/sof.h
> @@ -25,6 +25,7 @@ struct snd_sof_pdata {
>   	const char *drv_name;
>   	const char *name;
>   	const char *platform;
> +	const char *modelname;
>   
>   	struct device *dev;
>   
> diff --git a/sound/soc/sof/intel/hda.c b/sound/soc/sof/intel/hda.c
> index 91bd88fddac7..ccb640bacc99 100644
> --- a/sound/soc/sof/intel/hda.c
> +++ b/sound/soc/sof/intel/hda.c
> @@ -271,7 +271,7 @@ static int hda_init(struct snd_sof_dev *sdev)
>   	mutex_init(&hbus->prepare_mutex);
>   	hbus->pci = pci;
>   	hbus->mixer_assigned = -1;
> -	hbus->modelname = "sofbus";
> +	hbus->modelname = sdev->pdata->modelname;
>   
>   	/* initialise hdac bus */
>   	bus->addr = pci_resource_start(pci, 0);
> diff --git a/sound/soc/sof/sof-pci-dev.c b/sound/soc/sof/sof-pci-dev.c
> index bbeffd932de7..c01ad85aad2a 100644
> --- a/sound/soc/sof/sof-pci-dev.c
> +++ b/sound/soc/sof/sof-pci-dev.c
> @@ -34,6 +34,10 @@ static int sof_pci_debug;
>   module_param_named(sof_pci_debug, sof_pci_debug, int, 0444);
>   MODULE_PARM_DESC(sof_pci_debug, "SOF PCI debug options (0x0 all off)");
>   
> +static char *model;
> +module_param(model, charp, 0444);
> +MODULE_PARM_DESC(model, "Use the given HDA board model.");
> +
>   #define SOF_PCI_DISABLE_PM_RUNTIME BIT(0)
>   
>   #if IS_ENABLED(CONFIG_SND_SOC_SOF_APOLLOLAKE)
> @@ -326,6 +330,7 @@ static int sof_pci_probe(struct pci_dev *pci,
>   	sof_pdata->desc = (struct sof_dev_desc *)pci_id->driver_data;
>   	sof_pdata->dev = dev;
>   	sof_pdata->platform = dev_name(dev);
> +	sof_pdata->modelname = model;
>   
>   	/* alternate fw and tplg filenames ? */
>   	if (fw_path)
>