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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Charles Keepax <ckeepax@opensource.cirrus.com>,
        Vinod Koul <vkoul@kernel.org>, Takashi Iwai <tiwai@suse.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 17/78] ALSA: compress: Be more restrictive about when a drain is allowed
Date:   Thu, 22 Aug 2019 10:18:21 -0700
Message-Id: <20190822171832.543568472@linuxfoundation.org>
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[ Upstream commit 3b8179944cb0dd53e5223996966746cdc8a60657 ]

Draining makes little sense in the situation of hardware overrun, as the
hardware will have consumed all its available samples. Additionally,
draining whilst the stream is paused would presumably get stuck as no
data is being consumed on the DSP side.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 sound/core/compress_offload.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index d0a21a5867673..771d7b334ad87 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -749,7 +749,10 @@ static int snd_compr_drain(struct snd_compr_stream *stream)
 	case SNDRV_PCM_STATE_OPEN:
 	case SNDRV_PCM_STATE_SETUP:
 	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
 		return -EPERM;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
 	default:
 		break;
 	}
@@ -794,7 +797,10 @@ static int snd_compr_partial_drain(struct snd_compr_stream *stream)
 	case SNDRV_PCM_STATE_OPEN:
 	case SNDRV_PCM_STATE_SETUP:
 	case SNDRV_PCM_STATE_PREPARED:
+	case SNDRV_PCM_STATE_PAUSED:
 		return -EPERM;
+	case SNDRV_PCM_STATE_XRUN:
+		return -EPIPE;
 	default:
 		break;
 	}
-- 
2.20.1