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| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2011-04-22 15:13:54 +0200 | 
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2011-05-10 22:53:44 +0200 | 
| commit | f30e6d3e419bfb5540fa82ba7eca01d578556e6b (patch) | |
| tree | e4d6e7bad161a76b09557bf7513358ae1ce8f7fb /drivers/firewire/core-cdev.c | |
| parent | 020abf03cd659388f94cb328e1e1df0656e0d7ff (diff) | |
| download | olio-linux-3.10-f30e6d3e419bfb5540fa82ba7eca01d578556e6b.tar.xz olio-linux-3.10-f30e6d3e419bfb5540fa82ba7eca01d578556e6b.zip  | |
firewire: octlet AT payloads can be stack-allocated
We do not need slab allocations anymore in order to satisfy
streaming DMA mapping constraints, thanks to commit da28947e7e36
"firewire: ohci: avoid separate DMA mapping for small AT payloads".
(Besides, the slab-allocated buffers that firewire-core, firewire-sbp2,
and firedtv used to provide for 8-byte write and lock requests were
still not fully portable since they crossed cacheline boundaries or
shared a cacheline with unrelated CPU-accessed data.  snd-firewire-lib
got this aspect right by using an extra kmalloc/ kfree just for the
8-byte transaction buffer.)
This change replaces kmalloc'ed lock transaction scratch buffers in
firewire-core, firedtv, and snd-firewire-lib by local stack allocations.
Perhaps the most notable result of the change is simpler locking because
there is no need to serialize usages of preallocated per-device buffers
anymore.  Also, allocations and deallocations are simpler.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'drivers/firewire/core-cdev.c')
| -rw-r--r-- | drivers/firewire/core-cdev.c | 4 | 
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index 62ac111af24..2a3f1c4d690 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -141,7 +141,6 @@ struct iso_resource {  	int generation;  	u64 channels;  	s32 bandwidth; -	__be32 transaction_data[2];  	struct iso_resource_event *e_alloc, *e_dealloc;  }; @@ -1229,8 +1228,7 @@ static void iso_resource_work(struct work_struct *work)  			r->channels, &channel, &bandwidth,  			todo == ISO_RES_ALLOC ||  			todo == ISO_RES_REALLOC || -			todo == ISO_RES_ALLOC_ONCE, -			r->transaction_data); +			todo == ISO_RES_ALLOC_ONCE);  	/*  	 * Is this generation outdated already?  As long as this resource sticks  	 * in the idr, it will be scheduled again for a newer generation or at  |