diff options
| 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 /sound/firewire/iso-resources.c | |
| parent | 020abf03cd659388f94cb328e1e1df0656e0d7ff (diff) | |
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 'sound/firewire/iso-resources.c')
| -rw-r--r-- | sound/firewire/iso-resources.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/sound/firewire/iso-resources.c b/sound/firewire/iso-resources.c index 775dbd5f344..bb9c0c1fb52 100644 --- a/sound/firewire/iso-resources.c +++ b/sound/firewire/iso-resources.c @@ -11,7 +11,6 @@ #include <linux/jiffies.h> #include <linux/mutex.h> #include <linux/sched.h> -#include <linux/slab.h> #include <linux/spinlock.h> #include "iso-resources.h" @@ -25,10 +24,6 @@ */ int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit) { - r->buffer = kmalloc(2 * 4, GFP_KERNEL); - if (!r->buffer) - return -ENOMEM; - r->channels_mask = ~0uLL; r->unit = fw_unit_get(unit); mutex_init(&r->mutex); @@ -44,7 +39,6 @@ int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit) void fw_iso_resources_destroy(struct fw_iso_resources *r) { WARN_ON(r->allocated); - kfree(r->buffer); mutex_destroy(&r->mutex); fw_unit_put(r->unit); } @@ -131,7 +125,7 @@ retry_after_bus_reset: bandwidth = r->bandwidth + r->bandwidth_overhead; fw_iso_resource_manage(card, r->generation, r->channels_mask, - &channel, &bandwidth, true, r->buffer); + &channel, &bandwidth, true); if (channel == -EAGAIN) { mutex_unlock(&r->mutex); goto retry_after_bus_reset; @@ -184,7 +178,7 @@ int fw_iso_resources_update(struct fw_iso_resources *r) bandwidth = r->bandwidth + r->bandwidth_overhead; fw_iso_resource_manage(card, r->generation, 1uLL << r->channel, - &channel, &bandwidth, true, r->buffer); + &channel, &bandwidth, true); /* * When another bus reset happens, pretend that the allocation * succeeded; we will try again for the new generation later. @@ -220,7 +214,7 @@ void fw_iso_resources_free(struct fw_iso_resources *r) if (r->allocated) { bandwidth = r->bandwidth + r->bandwidth_overhead; fw_iso_resource_manage(card, r->generation, 1uLL << r->channel, - &channel, &bandwidth, false, r->buffer); + &channel, &bandwidth, false); if (channel < 0) dev_err(&r->unit->device, "isochronous resource deallocation failed\n"); |