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Commit 9f613601 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Greg Kroah-Hartman
Browse files

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: default avatarArnd Bergmann <arnd@arndb.de>
Cc: Markus Grabner <grabner@icg.tugraz.at>
Acked-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5c1f62a7

drivers/staging/line6/pcm.c

+15 −8
Original line number Original line Diff line number Diff line
@@ -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)

int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int channels)

{

{

	unsigned long flags_old =

	unsigned long flags_old, flags_new, flags_final;

	    __sync_fetch_and_or(&line6pcm->flags, channels);

	int err;

	unsigned long flags_new = flags_old | channels;



	unsigned long flags_final = flags_old;

	do {

	int err = 0;

		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;

	line6pcm->prev_fbuf = NULL;
@@ -197,9 +201,12 @@ int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int channels) 




int line6_pcm_release(struct snd_line6_pcm *line6pcm, int channels)

int line6_pcm_release(struct snd_line6_pcm *line6pcm, int channels)

{

{

	unsigned long flags_old =

	unsigned long flags_old, flags_new;

	    __sync_fetch_and_and(&line6pcm->flags, ~channels);



	unsigned long flags_new = flags_old & ~channels;

	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))

	if (test_flags(flags_new, flags_old, LINE6_BITS_CAPTURE_STREAM))

		line6_unlink_audio_in_urbs(line6pcm);

		line6_unlink_audio_in_urbs(line6pcm);