From: youling 257 <youling257@gmail.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: linux-xtensa@linux-xtensa.org, Michal Simek <monstr@monstr.eu>,
Vladimir Murzin <vladimir.murzin@arm.com>,
linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, Helge Deller <deller@gmx.de>,
x86@kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-m68k@lists.linux-m68k.org,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel@lists.infradead.org, hch@lst.de,
gregkh@google.com
Subject: Re: ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_*
Date: Mon, 4 Nov 2019 16:27:20 +0800 [thread overview]
Message-ID: <CAOzgRdYTa-nAa7QV6c2aZs910BACg91vAjcjw4V-Oy8KCZVmmQ@mail.gmail.com> (raw)
In-Reply-To: <s5himo0cbmm.wl-tiwai@suse.de>
This driver https://android.googlesource.com/kernel/common/+/refs/heads/android-mainline/drivers/usb/gadget/function/f_audio_source.c
2019-11-04 16:02 GMT+08:00, Takashi Iwai <tiwai@suse.de>:
> Exactly which driver is hit? The code path is via hw_support_mmap()
> and it's currently:
>
> static bool hw_support_mmap(struct snd_pcm_substream *substream)
> {
> if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP))
> return false;
>
> if (substream->ops->mmap ||
> substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_DEV)
> return true;
>
> return dma_can_mmap(substream->dma_buffer.dev.dev);
> }
>
> so at least the driver has already set the SNDRV_DMA_TYPE_DEV
> explicitly (it's non-zero) and some device object, but the device
> object was invalid for dma_can_mmap() call.
>
> This smells more like a driver-side issue, not in the core side.
>
>
> thanks,
>
> Takashi
>
next prev parent reply other threads:[~2019-11-04 8:27 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-04 7:06 ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_* youling 257
2019-11-04 8:02 ` Takashi Iwai
2019-11-04 8:27 ` youling 257 [this message]
2019-11-04 8:32 ` Greg Kroah-Hartman
2019-11-04 8:49 ` Greg Kroah-Hartman
2019-11-04 9:03 ` Takashi Iwai
-- strict thread matches above, loose matches on Subject: below --
2019-08-08 16:00 [PATCH 5/8] " Christoph Hellwig
2019-11-04 7:26 ` youling257
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