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

["Amadeusz Sławiński" <amadeuszx.slawinski@linux.intel.com>]

On 10/6/2022 10:45 AM, 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)
> 
> 
> So looking at this a bit more I see ...
> 
> [  199.422773] bad: scheduling from the idle thread!
> [  199.427610] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G      D  
> C         6.0.0-rc7-next-20220930-00007-gd6ae4ed0a78f-dirty #23
> [  199.438880] Hardware name: NVIDIA Jetson Nano Developer Kit (DT)
> [  199.444899] Call trace:
> [  199.447357]  dump_backtrace.part.7+0xe8/0xf8
> [  199.451680]  show_stack+0x14/0x38
> [  199.455024]  dump_stack_lvl+0x64/0x7c
> [  199.458715]  dump_stack+0x14/0x2c
> [  199.462067]  dequeue_task_idle+0x2c/0x58
> [  199.466038]  dequeue_task+0x38/0x98
> [  199.469565]  __schedule+0x4a4/0x6d8
> [  199.473104]  schedule+0x58/0xc0
> [  199.476292]  schedule_hrtimeout_range_clock+0x98/0x108
> [  199.481472]  schedule_hrtimeout_range+0x10/0x18
> [  199.486039]  usleep_range_state+0x7c/0xb0
> [  199.490084]  snd_hdac_stream_reset+0xe8/0x328 [snd_hda_core]
> [  199.495913]  snd_hdac_stream_sync+0xe4/0x190 [snd_hda_core]
> [  199.501627]  azx_pcm_trigger+0x1d8/0x250 [snd_hda_codec]
> [  199.507109]  snd_pcm_do_stop+0x54/0x70
> [  199.510904]  snd_pcm_action_single+0x44/0xa0
> [  199.515215]  snd_pcm_drain_done+0x20/0x28
> [  199.519267]  snd_pcm_update_state+0x114/0x128
> [  199.523670]  snd_pcm_update_hw_ptr0+0x22c/0x3a0
> [  199.528246]  snd_pcm_period_elapsed_under_stream_lock+0x44/0x88
> [  199.534216]  snd_pcm_period_elapsed+0x24/0x48
> [  199.538617]  stream_update+0x3c/0x50 [snd_hda_codec]
> [  199.543737]  snd_hdac_bus_handle_stream_irq+0xe8/0x150 [snd_hda_core]
> [  199.550320]  azx_interrupt+0xb4/0x1b0 [snd_hda_codec]
> [  199.555524]  __handle_irq_event_percpu+0x74/0x140
> [  199.560281]  handle_irq_event_percpu+0x14/0x48
> [  199.564772]  handle_irq_event+0x44/0x88
> [  199.568653]  handle_fasteoi_irq+0xa8/0x130
> [  199.572788]  generic_handle_domain_irq+0x28/0x40
> [  199.577452]  gic_handle_irq+0x9c/0xb8
> [  199.581168]  call_on_irq_stack+0x2c/0x40
> [  199.585129]  do_interrupt_handler+0x7c/0x80
> [  199.589355]  el1_interrupt+0x34/0x68
> [  199.592969]  el1h_64_irq_handler+0x14/0x20
> [  199.597107]  el1h_64_irq+0x64/0x68
> [  199.600540]  cpuidle_enter_state+0x130/0x2f8
> [  199.604853]  cpuidle_enter+0x38/0x50
> [  199.608463]  call_cpuidle+0x18/0x38
> [  199.611991]  do_idle+0x1f8/0x248
> [  199.615259]  cpu_startup_entry+0x20/0x28
> [  199.619224]  kernel_init+0x0/0x128
> [  199.622669]  arch_post_acpi_subsys_init+0x0/0x8
> [  199.627240]  start_kernel+0x630/0x668
> [  199.630933]  __primary_switched+0xb4/0xbc
> 
> 
> If I change your patch to be read_poll_timeout_atomic, then it works \o/
> 
> Can we make that update?
> 
> Jon
> 

Yes, it makes sense, as it uses udelay instead of usleep, same as 
original code.

I've send patch which updates the macros. It passed validation on our side.

Thanks for report!

Amadeusz