diff options
author | Arnd Bergmann <arnd@arndb.de> | 2013-06-21 21:55:35 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-24 15:56:09 -0700 |
commit | 9f613601482c56e05884f21565e3d218fac427ae (patch) | |
tree | 1c7ad18452c2f0811bc495e6bdd1245fd43ed810 /drivers/staging/line6 | |
parent | 5c1f62a75ca29d91606fd6e8bdeb2cff88086e0f (diff) |
staging: line6: avoid __sync_fetch_and_{and,or}
__sync_fetch_and_and and __sync_fetch_and_or are functions that are provided
by gcc and depending on the target architecture may be implemented in libgcc,
which is not always available in the kernel. This leads to a build failure
on ARMv5:
drivers/built-in.o: In function `line6_pcm_release':
:(.text+0x3bfe80): undefined reference to `__sync_fetch_and_and_4'
drivers/built-in.o: In function `line6_pcm_acquire':
:(.text+0x3bff30): undefined reference to `__sync_fetch_and_or_4'
To work around this, we can use the kernel-provided cmpxchg macro.
Build-tested only.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Markus Grabner <grabner@icg.tugraz.at>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/line6')
-rw-r--r-- | drivers/staging/line6/pcm.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/drivers/staging/line6/pcm.c b/drivers/staging/line6/pcm.c index 02f77d74809f..4795f1284906 100644 --- a/drivers/staging/line6/pcm.c +++ b/drivers/staging/line6/pcm.c @@ -107,11 +107,15 @@ static bool test_flags(unsigned long flags0, unsigned long flags1, int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int channels) { - unsigned long flags_old = - __sync_fetch_and_or(&line6pcm->flags, channels); - unsigned long flags_new = flags_old | channels; - unsigned long flags_final = flags_old; - int err = 0; + unsigned long flags_old, flags_new, flags_final; + int err; + + do { + flags_old = ACCESS_ONCE(line6pcm->flags); + flags_new = flags_old | channels; + } while (cmpxchg(&line6pcm->flags, flags_old, flags_new) != flags_old); + + flags_final = flags_old; line6pcm->prev_fbuf = NULL; @@ -197,9 +201,12 @@ pcm_acquire_error: int line6_pcm_release(struct snd_line6_pcm *line6pcm, int channels) { - unsigned long flags_old = - __sync_fetch_and_and(&line6pcm->flags, ~channels); - unsigned long flags_new = flags_old & ~channels; + unsigned long flags_old, flags_new; + + do { + flags_old = ACCESS_ONCE(line6pcm->flags); + flags_new = flags_old & ~channels; + } while (cmpxchg(&line6pcm->flags, flags_old, flags_new) != flags_old); if (test_flags(flags_new, flags_old, LINE6_BITS_CAPTURE_STREAM)) line6_unlink_audio_in_urbs(line6pcm); |