Re: Can anyone test with AMD onboard or HDMI/DP?

From: "Péter Ujfalusi" <peter.ujfalusi@linux.intel.com>
To: Takashi Iwai <tiwai@suse.de>, alsa-devel@alsa-project.org
Subject: Re: Can anyone test with AMD onboard or HDMI/DP?
Date: Fri, 17 Jun 2022 16:56:31 +0300	[thread overview]
Message-ID: <0920a0b2-31be-8629-07d0-564bb49dc60d@linux.intel.com> (raw)
In-Reply-To: <87bkur1nil.wl-tiwai@suse.de>

Hi Takashi,

On 17/06/2022 15:29, Takashi Iwai wrote:
> Hi,

Try #2, first mail did not made it through, I think.

> can anyone have an AMD onboard audio device and/or AMD HDMI/DP output
> for testing a patch below with 5.18.x or 5.19-rc kernels?  It's a
> pending fix (for 5.18+), but currently it can't be verified whether it
> causes a regression on the actual audio I/O (while it fixes the kernel
> crash).
> 
> If the generic allocator still doesn't work as expected here, it
> should show some audio stuttering or such effect.

But the fallback was needed for some machines using SOF to be able to
load the firmware...
like this:
https://github.com/thesofproject/linux/issues/3609

> 
> 
> Thanks!
> 
> Takashi
> 
> -- 8< --
> From: Takashi Iwai <tiwai@suse.de>
> Subject: [PATCH] ALSA: memalloc: Drop x86-specific hack for WC allocations
> 
> The recent report for a crash on Haswell machines implied that the
> x86-specific (rather hackish) implementation for write-cache memory
> buffer allocation in ALSA core is buggy with the recent kernel in some
> corner cases.  This patch drops the x86-specific implementation and
> uses the standard dma_alloc_wc() & co generically for avoiding the bug
> and also for simplification.
> 
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216112
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  sound/core/memalloc.c | 23 +----------------------
>  1 file changed, 1 insertion(+), 22 deletions(-)
> 
> diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
> index 15dc7160ba34..8cfdaee77905 100644
> --- a/sound/core/memalloc.c
> +++ b/sound/core/memalloc.c
> @@ -431,33 +431,17 @@ static const struct snd_malloc_ops snd_dma_iram_ops = {
>   */
>  static void *snd_dma_dev_alloc(struct snd_dma_buffer *dmab, size_t size)
>  {
> -	void *p;
> -
> -	p = dma_alloc_coherent(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
> -#ifdef CONFIG_X86
> -	if (p && dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC)
> -		set_memory_wc((unsigned long)p, PAGE_ALIGN(size) >> PAGE_SHIFT);
> -#endif
> -	return p;
> +	return dma_alloc_coherent(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
>  }
>  
>  static void snd_dma_dev_free(struct snd_dma_buffer *dmab)
>  {
> -#ifdef CONFIG_X86
> -	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC)
> -		set_memory_wb((unsigned long)dmab->area,
> -			      PAGE_ALIGN(dmab->bytes) >> PAGE_SHIFT);
> -#endif
>  	dma_free_coherent(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
>  }
>  
>  static int snd_dma_dev_mmap(struct snd_dma_buffer *dmab,
>  			    struct vm_area_struct *area)
>  {
> -#ifdef CONFIG_X86
> -	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC)
> -		area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
> -#endif
>  	return dma_mmap_coherent(dmab->dev.dev, area,
>  				 dmab->area, dmab->addr, dmab->bytes);
>  }
> @@ -471,10 +455,6 @@ static const struct snd_malloc_ops snd_dma_dev_ops = {
>  /*
>   * Write-combined pages
>   */
> -#ifdef CONFIG_X86
> -/* On x86, share the same ops as the standard dev ops */
> -#define snd_dma_wc_ops	snd_dma_dev_ops
> -#else /* CONFIG_X86 */
>  static void *snd_dma_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
>  {
>  	return dma_alloc_wc(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
> @@ -497,7 +477,6 @@ static const struct snd_malloc_ops snd_dma_wc_ops = {
>  	.free = snd_dma_wc_free,
>  	.mmap = snd_dma_wc_mmap,
>  };
> -#endif /* CONFIG_X86 */
>  
>  #ifdef CONFIG_SND_DMA_SGBUF
>  static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size);

-- 
Péter