2022-03-02 18:24:39

by Zhen Ni

Subject: [PATCH] ALSA: intel_hdmi: Fix reference to PCM buffer address

PCM buffers might be allocated dynamically when the buffer
preallocation failed or a larger buffer is requested, and it's not
guaranteed that substream->dma_buffer points to the actually used
buffer. The driver needs to refer to substream->runtime->dma_addr
instead for the buffer address.

Signed-off-by: Zhen Ni <[email protected]>
---
sound/x86/intel_hdmi_audio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
index 1c94eaff1931..4a3ff6468aa7 100644
--- a/sound/x86/intel_hdmi_audio.c
+++ b/sound/x86/intel_hdmi_audio.c
@@ -1261,7 +1261,7 @@ static int had_pcm_mmap(struct snd_pcm_substream *substream,
{
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
return remap_pfn_range(vma, vma->vm_start,
- substream->dma_buffer.addr >> PAGE_SHIFT,
+ substream->runtime->dma_addr >> PAGE_SHIFT,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
}

--
2.20.1

2022-03-03 00:22:50

by Takashi Iwai

Subject: Re: [PATCH] ALSA: intel_hdmi: Fix reference to PCM buffer address

On Wed, 02 Mar 2022 08:42:41 +0100,
Zhen Ni wrote:
>
> PCM buffers might be allocated dynamically when the buffer
> preallocation failed or a larger buffer is requested, and it's not
> guaranteed that substream->dma_buffer points to the actually used
> buffer. The driver needs to refer to substream->runtime->dma_addr
> instead for the buffer address.
>
> Signed-off-by: Zhen Ni <[email protected]>

Thanks, applied now with Cc-to-stable.

I guess the had_pcm_mmap() can be dropped completely and replaced with
the standard mmap helper, as what we really want is rather wc.
But it can be done for 5.18.


Takashi