Commit 636eb9cb authored by Brian Swetland's avatar Brian Swetland Committed by Daniel Walker
Browse files

msm: smd: provide atomic channel writes 



Some smd clients may write from multiple threads, in which case it's
not safe to call smd_write without holding a lock.  smd_write_atomic()
provides the same functionality as smd_write() but obtains the smd
lock first.

Signed-off-by: default avatarBrian Swetland <swetland@google.com>
Signed-off-by: default avatarDaniel Walker <dwalker@codeaurora.org>
parent 1207babd

arch/arm/mach-msm/include/mach/msm_smd.h

+1 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ int smd_read(smd_channel_t *ch, void *data, int len); 
** it will return the requested length written or an error.

*/

int smd_write(smd_channel_t *ch, const void *data, int len);

int smd_write_atomic(smd_channel_t *ch, const void *data, int len);



int smd_write_avail(smd_channel_t *ch);

int smd_read_avail(smd_channel_t *ch);

arch/arm/mach-msm/smd.c

+10 −0
Original line number Diff line number Diff line
@@ -804,6 +804,16 @@ int smd_write(smd_channel_t *ch, const void *data, int len) 
	return ch->write(ch, data, len);

}



int smd_write_atomic(smd_channel_t *ch, const void *data, int len)

{

	unsigned long flags;

	int res;

	spin_lock_irqsave(&smd_lock, flags);

	res = ch->write(ch, data, len);

	spin_unlock_irqrestore(&smd_lock, flags);

	return res;

}



int smd_read_avail(smd_channel_t *ch)

{

	return ch->read_avail(ch);

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