[ALSA] Don't reject O_RDWR at opening PCM OSS with read/write-only device

Accept O_RDWR at opening a PCM OSS device that is read- or write-only,
just for the compatibility with the behavior of older versions.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index f5ff4f4a16ee0b7964599c49f1311176dc7a6aa1..472fce0ee0e8111210e68ead84424f4f477635f2 100644 (file)
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2228,6 +2228,8 @@ static int snd_pcm_oss_open_file(struct file *file,
        for (idx = 0; idx < 2; idx++) {
                if (setup[idx].disable)
                        continue;
+               if (! pcm->streams[idx].substream_count)
+                       continue; /* no matching substream */
                if (idx == SNDRV_PCM_STREAM_PLAYBACK) {
                        if (! (f_mode & FMODE_WRITE))
                                continue;