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;
Subject: Re: [RFC PATCH 0/3] Separate BE DAI HW constraints from FE ones
To:     Codrin Ciubotariu <codrin.ciubotariu@microchip.com>,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Cc:     tiwai@suse.com, lgirdwood@gmail.com, broonie@kernel.org,
        mirq-linux@rere.qmqm.pl, gustavoars@kernel.org
References: <20210323114327.3969072-1-codrin.ciubotariu@microchip.com>
From:   Jaroslav Kysela <perex@perex.cz>
Message-ID: <a0c862ec-44ba-52e0-551c-0347166ac4e9@perex.cz>
Date:   Tue, 23 Mar 2021 13:15:42 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.0
MIME-Version: 1.0
In-Reply-To: <20210323114327.3969072-1-codrin.ciubotariu@microchip.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Dne 23. 03. 21 v 12:43 Codrin Ciubotariu napsal(a):

> To achieve this, the first thing needed is to detect whether a HW
> constraint rule is enforced by a FE or a BE DAI. This means that
> snd_pcm_hw_rule_add() needs to be able to differentiate between the two
> type of DAIs. For this, the runtime pointer to struct snd_pcm_runtime is
> replaced with a pointer to struct snd_pcm_substream, to be able to reach
> substream->pcm->internal to differentiate between FE and BE DAIs.

Think about other not-so-invasive solution. What about to use
'runtime->private_data' (struct snd_soc_pcm_runtime *) to determine FE / BE?

					Jaroslav
-- 
Jaroslav Kysela <perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.