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authorStefan Richter <stefanr@s5r6.in-berlin.de>2011-04-22 15:13:54 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2011-05-10 22:53:44 +0200
commitf30e6d3e419bfb5540fa82ba7eca01d578556e6b (patch)
treee4d6e7bad161a76b09557bf7513358ae1ce8f7fb /sound
parent020abf03cd659388f94cb328e1e1df0656e0d7ff (diff)
downloadlinux-f30e6d3e419bfb5540fa82ba7eca01d578556e6b.tar.gz
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')
-rw-r--r--sound/firewire/cmp.c3
-rw-r--r--sound/firewire/iso-resources.c12
-rw-r--r--sound/firewire/iso-resources.h1
3 files changed, 4 insertions, 12 deletions
diff --git a/sound/firewire/cmp.c b/sound/firewire/cmp.c
index 4a37f3a6fab..14cacbc655d 100644
--- a/sound/firewire/cmp.c
+++ b/sound/firewire/cmp.c
@@ -49,10 +49,9 @@ static int pcr_modify(struct cmp_connection *c,
enum bus_reset_handling bus_reset_handling)
{
struct fw_device *device = fw_parent_device(c->resources.unit);
- __be32 *buffer = c->resources.buffer;
int generation = c->resources.generation;
int rcode, errors = 0;
- __be32 old_arg;
+ __be32 old_arg, buffer[2];
int err;
buffer[0] = c->last_pcr_value;
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");
diff --git a/sound/firewire/iso-resources.h b/sound/firewire/iso-resources.h
index 3f0730e4d84..5a9af7c6165 100644
--- a/sound/firewire/iso-resources.h
+++ b/sound/firewire/iso-resources.h
@@ -24,7 +24,6 @@ struct fw_iso_resources {
unsigned int bandwidth_overhead;
int generation; /* in which allocation is valid */
bool allocated;
- __be32 *buffer;
};
int fw_iso_resources_init(struct fw_iso_resources *r,