ALSA: rawmidi: Check stream state at exported functions
The rawmidi interface provides some exported functions to be called
from outside, and currently there is no state check for those calls
whether the stream is properly opened and running. Although such an
invalid call shouldn't happen, but who knows.
This patch adds the proper rawmidi stream state checks with spinlocks
for avoiding unexpected accesses when such exported functions are
called in an invalid state. After this patch, with the
substream->opened and substream->runtime are always tied and
guaranteed to be set under substream->lock.
Link: https://lore.kernel.org/r/20220617144051.18985-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>