Re: [PATCH v2 2/4] ALSA: hda: Rework snd_hdac_stream_reset() to use macros

[Jon Hunter <jonathanh@nvidia.com>]

On 05/10/2022 15:07, Takashi Iwai wrote:
> On Wed, 05 Oct 2022 15:52:01 +0200,
> Jon Hunter wrote:
>>
>>
>> On 05/10/2022 13:29, Takashi Iwai wrote:
>>
>> ...
>>
>>>> HDA playback is failing on -next for various Tegra boards. Bisect is
>>>> point to this commit and reverting it fixes the problem. I was a bit
>>>> puzzled why this change is causing a problem, but looking closer there
>>>> is a difference between the previous code that was calling
>>>> snd_hdac_stream_readb() and the new code that is calling
>>>> snd_hdac_stream_readb_poll(). The function snd_hdac_stream_readb()
>>>> calls snd_hdac_aligned_mmio() is see if the device has an aligned MMIO
>>>> which Tegra does and then would call snd_hdac_aligned_read(). However,
>>>> now the code always call readb() and this is breaking Tegra.
>>>>
>>>> So it is either necessary to update snd_hdac_stream_readb_poll() to
>>>> handle this or revert this change.
>>>
>>> Does the patch below work?
>>>
>>>
>>> thanks,
>>>
>>> Takashi
>>>
>>> -- 8< --
>>> --- a/include/sound/hdaudio.h
>>> +++ b/include/sound/hdaudio.h
>>> @@ -592,8 +592,8 @@ int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus,
>>>    #define snd_hdac_stream_readb(dev, reg) \
>>>    	snd_hdac_reg_readb((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)
>>>    #define snd_hdac_stream_readb_poll(dev, reg, val, cond, delay_us, timeout_us) \
>>> -	readb_poll_timeout((dev)->sd_addr + AZX_REG_ ## reg, val, cond, \
>>> -			   delay_us, timeout_us)
>>> +	read_poll_timeout(snd_hdac_reg_readb, val, cond, delay_us, timeout_us,\
>>> +			  false, (dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)
>>>    #define snd_hdac_stream_readl_poll(dev, reg, val, cond, delay_us, timeout_us) \
>>>    	readl_poll_timeout((dev)->sd_addr + AZX_REG_ ## reg, val, cond, \
>>>    			   delay_us, timeout_us)
>>
>>
>> Amazingly it does not work. I would have thought that would, but it
>> does not. I am a bit puzzled by that?
> 
> Interesting, it must be a subtle difference.
> What about passing true?  It seems that the original code has the
> udelay(3) before the loop.


I wondered the same and tried that, but still not working.

Jon

-- 
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