Re: [PATCH 2/4] ALSA: hda: Using polling mode for loongson controller by default

[Takashi Iwai <tiwai@suse.de>]

On Wed, 31 May 2023 05:21:32 +0200,
Yanteng Si wrote:
> 
> On loongson controller, RIRBSTS.RINTFL cannot be cleared,
> azx_interrupt() is called all the time. We disable RIRB
> interrupt, and use polling mode by default.
> 
> Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
> Signed-off-by: Yingkun Meng <mengyingkun@loongson.cn>
> ---
>  sound/hda/hdac_controller.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
> index 3c7af6558249..dbaa19cb8162 100644
> --- a/sound/hda/hdac_controller.c
> +++ b/sound/hda/hdac_controller.c
> @@ -10,6 +10,7 @@
>  #include <sound/hdaudio.h>
>  #include <sound/hda_register.h>
>  #include "local.h"
> +#include "../pci/hda/hda_controller.h"
>  
>  /* clear CORB read pointer properly */
>  static void azx_clear_corbrp(struct hdac_bus *bus)
> @@ -42,6 +43,8 @@ static void azx_clear_corbrp(struct hdac_bus *bus)
>   */
>  void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
>  {
> +	struct azx *chip = bus_to_azx(bus);

You can't convert in this way in the generic HD-audio bus code in
sound/hda/*.  The struct azx is specific to sound/pci/hda/*.


>  	WARN_ON_ONCE(!bus->rb.area);
>  
>  	spin_lock_irq(&bus->reg_lock);
> @@ -79,7 +82,10 @@ void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
>  	/* set N=1, get RIRB response interrupt for new entry */
>  	snd_hdac_chip_writew(bus, RINTCNT, 1);
>  	/* enable rirb dma and response irq */
> -	snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN | AZX_RBCTL_IRQ_EN);
> +	if (chip->driver_caps & AZX_DCAPS_LOONGSON_WORKAROUND)
> +		snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN);
> +	else
> +		snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN | AZX_RBCTL_IRQ_EN);

That is, for some device-specific workaround like this, you'd need to
introduce a new flag in struct hdac_bus, set up in the
sound/pci/hda/hda_intel.c instead.


thanks,

Takashi