[PATCH v3 3/9] ALSA: hda: Introduce snd_hdac_stream_wait_drsm()

[Amadeusz Sławiński]

On 10/27/2022 1:05 PM, Takashi Iwai wrote:
> On Thu, 27 Oct 2022 12:29:35 +0200,
> Amadeusz Sławiński wrote:
>>
>> On 10/27/2022 12:21 PM, Takashi Iwai wrote:
>>> On Thu, 27 Oct 2022 10:23:25 +0200,
>>> Cezary Rojewski wrote:
>>>> --- a/sound/hda/hdac_stream.c
>>>> +++ b/sound/hda/hdac_stream.c
>>>> @@ -821,6 +821,27 @@ void snd_hdac_stream_drsm_enable(struct hdac_bus *bus,
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(snd_hdac_stream_drsm_enable);
>>>>    +/*
>>>> + * snd_hdac_stream_wait_drsm - wait for HW to clear RSM for a stream
>>>> + * @azx_dev: HD-audio core stream to await RSM for
>>>> + *
>>>> + * Returns 0 on success and -ETIMEDOUT upon a timeout.
>>>> + */
>>>> +int snd_hdac_stream_wait_drsm(struct hdac_stream *azx_dev)
>>>> +{
>>>> +	struct hdac_bus *bus = azx_dev->bus;
>>>> +	u32 mask, reg;
>>>> +	int ret;
>>>> +
>>>> +	mask = 1 << azx_dev->index;
>>>> +
>>>> +	ret = readb_poll_timeout(bus->drsmcap + AZX_REG_DRSM_CTL, reg, !(reg & mask), 250, 2000);
>>>
>>> Remember that HD-audio bus doesn't always allow readb().  Tegra
>>> requires the aligned access, for example.
>>>
>>
>> The readb_poll_timeout macro was updated to take care of that,
>> https://lore.kernel.org/all/20221007084856.1638302-1-amadeuszx.slawinski@linux.intel.com/
>> so it should be fine?
> 
> This patch doesn't use that macro...
> 

Ah... right, sorry for confusion, I looked at diff part instead of macro 
name.