From f30e6d3e419bfb5540fa82ba7eca01d578556e6b Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Fri, 22 Apr 2011 15:13:54 +0200 Subject: 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 Acked-by: Clemens Ladisch --- drivers/firewire/core-cdev.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/firewire/core-cdev.c') 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transaction_data); + todo == ISO_RES_ALLOC_ONCE); /* * Is this generation outdated already?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 -- cgit v1.2.3