Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 25 Feb 2021 11:55:44 +0100
Message-ID: <s5h35xkquvj.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Anton Yakovlev <anton.yakovlev@opensynergy.com>
Cc:     <virtualization@lists.linux-foundation.org>,
        <alsa-devel@alsa-project.org>, <virtio-dev@lists.oasis-open.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 6/9] ALSA: virtio: PCM substream operators
In-Reply-To: <20210222153444.348390-7-anton.yakovlev@opensynergy.com>
References: <20210222153444.348390-1-anton.yakovlev@opensynergy.com>
        <20210222153444.348390-7-anton.yakovlev@opensynergy.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka)
 FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3
 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO)
MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka")
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Mon, 22 Feb 2021 16:34:41 +0100,
Anton Yakovlev wrote:
> +static int virtsnd_pcm_open(struct snd_pcm_substream *substream)
> +{
> +	struct virtio_pcm *vpcm = snd_pcm_substream_chip(substream);
> +	struct virtio_pcm_substream *vss = NULL;
> +
> +	if (vpcm) {
> +		switch (substream->stream) {
> +		case SNDRV_PCM_STREAM_PLAYBACK:
> +		case SNDRV_PCM_STREAM_CAPTURE: {

The switch() here looks superfluous.  The substream->stream must be a
good value in the callback.  If any, you can put WARN_ON() there, but
I don't think it worth.

> +static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream,
> +				 struct snd_pcm_hw_params *hw_params)
> +{
....
> +	return virtsnd_pcm_msg_alloc(vss, periods, period_bytes);

We have the allocation, but...

> +static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream)
> +{
> +	return 0;

... no release at hw_free()?
I know that the free is present in the allocator, but it's only for
re-allocation case, I suppose.


thanks,

Takashi