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;
IronPort-SDR: DXWrj4D6QxmPMjSDEUbP/eQlZ609YXzRhFhJPONYMHOYAseOG1cqHZcp8Ga3P6djR7ZgDzxi0m
 CoRJtWEiR3hQ==
IronPort-SDR: ePrJxyatEex3FEpv9afxriiqBih7gHrglUBpHtZohFczib72VOgz7E5Oo1dCTZAQbBh8ZCH+JW
 Ta5022Q17Ubw==
From:   Bard Liao <yung-chuan.liao@linux.intel.com>
To:     alsa-devel@alsa-project.org, vkoul@kernel.org
Cc:     vinod.koul@linaro.org, linux-kernel@vger.kernel.org, tiwai@suse.de,
        broonie@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com,
        srinivas.kandagatla@linaro.org, rander.wang@linux.intel.com,
        ranjani.sridharan@linux.intel.com, hui.wang@canonical.com,
        pierre-louis.bossart@linux.intel.com, sanyog.r.kale@intel.com,
        mengdong.lin@intel.com, bard.liao@intel.com
Subject: [PATCH v3 1/3] ASoC: soc-dai: clarify return value for get_sdw_stream()
Date:   Sat,  5 Sep 2020 02:28:52 +0800
Message-Id: <20200904182854.3944-2-yung-chuan.liao@linux.intel.com>
In-Reply-To: <20200904182854.3944-1-yung-chuan.liao@linux.intel.com>
References: <20200904182854.3944-1-yung-chuan.liao@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

Previous changes move to use ERR_PTR(-ENOTSUPP), but it's not clear
what implementations can return in case of errors. Explicitly document
that NULL is not a possible return value, only ERR_PTR with a negative
error code is valid.

Fixes: 308811a327c38 ('ASoC: soc-dai: return proper error for get_sdw_stream()')
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reported-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 include/sound/soc-dai.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index 776a60529e70..8b693dade9c6 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -471,7 +471,8 @@ static inline int snd_soc_dai_set_sdw_stream(struct snd_soc_dai *dai,
  * This routine only retrieves that was previously configured
  * with snd_soc_dai_get_sdw_stream()
  *
- * Returns pointer to stream or -ENOTSUPP if callback is not supported;
+ * Returns pointer to stream or an ERR_PTR value, e.g.
+ * ERR_PTR(-ENOTSUPP) if callback is not supported;
  */
 static inline void *snd_soc_dai_get_sdw_stream(struct snd_soc_dai *dai,
 					       int direction)
-- 
2.17.1