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V4L/DVB (11616): cx18: Add a work queue for deferring empty buffer handoffs to the firmware

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This change defers sending all CX18_CPU_DE_SET_MDL commands, for a stream with
an ongoing capture, by adding a work queue to handle sending such commands when
needed.  This prevents any sleeps, caused by notifying the firmware of new
usable buffers, when a V4L2 application read() is being satisfied or when
an incoming buffer is processed by the cx18-NN-in work queue thread.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Andy Walls 2009-04-13 22:42:43 -03:00 committed by Mauro Carvalho Chehab
parent deed75ed9f
commit 8711615951
4 changed files with 202 additions and 26 deletions
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92
drivers/media/video/cx18/cx18-driver.c
View file

@ -546,6 +546,47 @@ done:
cx->card_i2c = cx->card->i2c;
}
static int __devinit cx18_create_in_workq(struct cx18 *cx)
{
snprintf(cx->in_workq_name, sizeof(cx->in_workq_name), "%s-in",
cx->v4l2_dev.name);
cx->in_work_queue = create_singlethread_workqueue(cx->in_workq_name);
if (cx->in_work_queue == NULL) {
CX18_ERR("Unable to create incoming mailbox handler thread\n");
return -ENOMEM;
}
return 0;
}
static int __devinit cx18_create_out_workq(struct cx18 *cx)
{
snprintf(cx->out_workq_name, sizeof(cx->out_workq_name), "%s-out",
cx->v4l2_dev.name);
cx->out_work_queue = create_workqueue(cx->out_workq_name);
if (cx->out_work_queue == NULL) {
CX18_ERR("Unable to create outgoing mailbox handler threads\n");
return -ENOMEM;
}
return 0;
}
static void __devinit cx18_init_in_work_orders(struct cx18 *cx)
{
int i;
for (i = 0; i < CX18_MAX_IN_WORK_ORDERS; i++) {
cx->in_work_order[i].cx = cx;
cx->in_work_order[i].str = cx->epu_debug_str;
INIT_WORK(&cx->in_work_order[i].work, cx18_in_work_handler);
}
}
static void __devinit cx18_init_out_work_orders(struct cx18 *cx)
{
int i;
for (i = 0; i < CX18_MAX_OUT_WORK_ORDERS; i++)
INIT_WORK(&cx->out_work_order[i].work, cx18_out_work_handler);
}
/* Precondition: the cx18 structure has been memset to 0. Only
the dev and instance fields have been filled in.
No assumptions on the card type may be made here (see cx18_init_struct2
@ -553,7 +594,7 @@ done:
*/
static int __devinit cx18_init_struct1(struct cx18 *cx)
{
int i;
int ret;
cx->base_addr = pci_resource_start(cx->pci_dev, 0);
@ -562,19 +603,18 @@ static int __devinit cx18_init_struct1(struct cx18 *cx)
mutex_init(&cx->epu2apu_mb_lock);
mutex_init(&cx->epu2cpu_mb_lock);
snprintf(cx->in_workq_name, sizeof(cx->in_workq_name), "%s-in",
cx->v4l2_dev.name);
cx->in_work_queue = create_singlethread_workqueue(cx->in_workq_name);
if (cx->in_work_queue == NULL) {
CX18_ERR("Unable to create incoming mailbox handler thread\n");
return -ENOMEM;
ret = cx18_create_out_workq(cx);
if (ret)
return ret;
ret = cx18_create_in_workq(cx);
if (ret) {
destroy_workqueue(cx->out_work_queue);
return ret;
}
for (i = 0; i < CX18_MAX_IN_WORK_ORDERS; i++) {
cx->in_work_order[i].cx = cx;
cx->in_work_order[i].str = cx->epu_debug_str;
INIT_WORK(&cx->in_work_order[i].work, cx18_in_work_handler);
}
cx18_init_out_work_orders(cx);
cx18_init_in_work_orders(cx);
/* start counting open_id at 1 */
cx->open_id = 1;
@ -761,17 +801,17 @@ static int __devinit cx18_probe(struct pci_dev *pci_dev,
retval = -ENODEV;
goto err;
}
if (cx18_init_struct1(cx)) {
retval = -ENOMEM;
retval = cx18_init_struct1(cx);
if (retval)
goto err;
}
CX18_DEBUG_INFO("base addr: 0x%08x\n", cx->base_addr);
/* PCI Device Setup */
retval = cx18_setup_pci(cx, pci_dev, pci_id);
if (retval != 0)
goto free_workqueue;
goto free_workqueues;
/* map io memory */
CX18_DEBUG_INFO("attempting ioremap at 0x%08x len 0x%08x\n",
@ -945,8 +985,9 @@ free_map:
cx18_iounmap(cx);
free_mem:
release_mem_region(cx->base_addr, CX18_MEM_SIZE);
free_workqueue:
free_workqueues:
destroy_workqueue(cx->in_work_queue);
destroy_workqueue(cx->out_work_queue);
err:
if (retval == 0)
retval = -ENODEV;
@ -1075,15 +1116,26 @@ static void cx18_remove(struct pci_dev *pci_dev)
if (atomic_read(&cx->tot_capturing) > 0)
cx18_stop_all_captures(cx);
/* Interrupts */
/* Stop interrupts that cause incoming work to be queued */
cx18_sw1_irq_disable(cx, IRQ_CPU_TO_EPU | IRQ_APU_TO_EPU);
/* Incoming work can cause outgoing work, so clean up incoming first */
cx18_cancel_in_work_orders(cx);
/*
* An outgoing work order can have the only pointer to a dynamically
* allocated buffer, so we need to flush outgoing work and not just
* cancel it, so we don't lose the pointer and leak memory.
*/
flush_workqueue(cx->out_work_queue);
/* Stop ack interrupts that may have been needed for work to finish */
cx18_sw2_irq_disable(cx, IRQ_CPU_TO_EPU_ACK | IRQ_APU_TO_EPU_ACK);
cx18_halt_firmware(cx);
cx18_cancel_in_work_orders(cx);
destroy_workqueue(cx->in_work_queue);
destroy_workqueue(cx->out_work_queue);
cx18_streams_cleanup(cx, 1);

32
drivers/media/video/cx18/cx18-driver.h
View file

@ -254,6 +254,7 @@ struct cx18_options {
#define CX18_F_S_INTERNAL_USE 5 /* this stream is used internally (sliced VBI processing) */
#define CX18_F_S_STREAMOFF 7 /* signal end of stream EOS */
#define CX18_F_S_APPL_IO 8 /* this stream is used read/written by an application */
#define CX18_F_S_STOPPING 9 /* telling the fw to stop capturing */
/* per-cx18, i_flags */
#define CX18_F_I_LOADED_FW 0 /* Loaded firmware 1st time */
@ -324,6 +325,33 @@ struct cx18_in_work_order {
char *str;
};
/*
* There are 2 types of deferrable tasks that send messages out to the firmware:
* 1. Sending individual buffers back to the firmware
* 2. Sending as many free buffers for a stream from q_free as we can to the fw
*
* The worst case scenario for multiple simultaneous streams is
* TS, YUV, PCM, VBI, MPEG, and IDX all going at once.
*
* We try to load the firmware queue with as many free buffers as possible,
* whenever we get a buffer back for a stream. For the TS we return the single
* buffer to the firmware at that time as well. For all other streams, we
* return single buffers to the firmware as the application drains them.
*
* 6 streams * 2 sets of orders * (1 single buf + 1 load fw from q_free)
* = 24 work orders should cover our needs, provided the applications read
* at a fairly steady rate. If apps don't, we fall back to non-deferred
* operation, when no cx18_out_work_orders are available for use.
*/
#define CX18_MAX_OUT_WORK_ORDERS (24)
struct cx18_out_work_order {
struct work_struct work;
atomic_t pending;
struct cx18_stream *s;
struct cx18_buffer *buf; /* buf == NULL, means load fw from q_free */
};
#define CX18_INVALID_TASK_HANDLE 0xffffffff
struct cx18_stream {
@ -573,6 +601,10 @@ struct cx18 {
struct cx18_in_work_order in_work_order[CX18_MAX_IN_WORK_ORDERS];
char epu_debug_str[256]; /* CX18_EPU_DEBUG is rare: use shared space */
struct workqueue_struct *out_work_queue;
char out_workq_name[12]; /* "cx18-NN-out" */
struct cx18_out_work_order out_work_order[CX18_MAX_OUT_WORK_ORDERS];
/* i2c */
struct i2c_adapter i2c_adap[2];
struct i2c_algo_bit_data i2c_algo[2];

99
drivers/media/video/cx18/cx18-streams.c
View file

@ -431,14 +431,16 @@ static void cx18_vbi_setup(struct cx18_stream *s)
cx18_api(cx, CX18_CPU_SET_RAW_VBI_PARAM, 6, data);
}
struct cx18_queue *cx18_stream_put_buf_fw(struct cx18_stream *s,
struct cx18_buffer *buf)
static
struct cx18_queue *_cx18_stream_put_buf_fw(struct cx18_stream *s,
struct cx18_buffer *buf)
{
struct cx18 *cx = s->cx;
struct cx18_queue *q;
/* Don't give it to the firmware, if we're not running a capture */
if (s->handle == CX18_INVALID_TASK_HANDLE ||
test_bit(CX18_F_S_STOPPING, &s->s_flags) ||
!test_bit(CX18_F_S_STREAMING, &s->s_flags))
return cx18_enqueue(s, buf, &s->q_free);
@ -453,7 +455,8 @@ struct cx18_queue *cx18_stream_put_buf_fw(struct cx18_stream *s,
return q;
}
void cx18_stream_load_fw_queue(struct cx18_stream *s)
static
void _cx18_stream_load_fw_queue(struct cx18_stream *s)
{
struct cx18_queue *q;
struct cx18_buffer *buf;
@ -467,11 +470,93 @@ void cx18_stream_load_fw_queue(struct cx18_stream *s)
buf = cx18_dequeue(s, &s->q_free);
if (buf == NULL)
break;
q = cx18_stream_put_buf_fw(s, buf);
q = _cx18_stream_put_buf_fw(s, buf);
} while (atomic_read(&s->q_busy.buffers) < CX18_MAX_FW_MDLS_PER_STREAM
&& q == &s->q_busy);
}
static inline
void free_out_work_order(struct cx18_out_work_order *order)
{
atomic_set(&order->pending, 0);
}
void cx18_out_work_handler(struct work_struct *work)
{
struct cx18_out_work_order *order =
container_of(work, struct cx18_out_work_order, work);
struct cx18_stream *s = order->s;
struct cx18_buffer *buf = order->buf;
free_out_work_order(order);
if (buf == NULL)
_cx18_stream_load_fw_queue(s);
else
_cx18_stream_put_buf_fw(s, buf);
}
static
struct cx18_out_work_order *alloc_out_work_order(struct cx18 *cx)
{
int i;
struct cx18_out_work_order *order = NULL;
for (i = 0; i < CX18_MAX_OUT_WORK_ORDERS; i++) {
/*
* We need "pending" to be atomic to inspect & set its contents
* 1. "pending" is only set to 1 here, but needs multiple access
* protection
* 2. work handler threads only clear "pending" and only
* on one, particular work order at a time, per handler thread.
*/
if (atomic_add_unless(&cx->out_work_order[i].pending, 1, 1)) {
order = &cx->out_work_order[i];
break;
}
}
return order;
}
struct cx18_queue *cx18_stream_put_buf_fw(struct cx18_stream *s,
struct cx18_buffer *buf)
{
struct cx18 *cx = s->cx;
struct cx18_out_work_order *order;
order = alloc_out_work_order(cx);
if (order == NULL) {
CX18_DEBUG_WARN("No blank, outgoing-mailbox, deferred-work, "
"order forms available; sending buffer %u back "
"to the firmware immediately for stream %s\n",
buf->id, s->name);
return _cx18_stream_put_buf_fw(s, buf);
}
order->s = s;
order->buf = buf;
queue_work(cx->out_work_queue, &order->work);
return NULL;
}
void cx18_stream_load_fw_queue(struct cx18_stream *s)
{
struct cx18 *cx = s->cx;
struct cx18_out_work_order *order;
order = alloc_out_work_order(cx);
if (order == NULL) {
CX18_DEBUG_WARN("No blank, outgoing-mailbox, deferred-work, "
"order forms available; filling the firmware "
"buffer queue immediately for stream %s\n",
s->name);
_cx18_stream_load_fw_queue(s);
return;
}
order->s = s;
order->buf = NULL; /* Indicates to load the fw queue */
queue_work(cx->out_work_queue, &order->work);
}
int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
{
u32 data[MAX_MB_ARGUMENTS];
@ -607,12 +692,13 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
cx18_writel(cx, s->buf_size, &cx->scb->cpu_mdl[buf->id].length);
}
mutex_unlock(&s->qlock);
cx18_stream_load_fw_queue(s);
_cx18_stream_load_fw_queue(s);
/* begin_capture */
if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) {
CX18_DEBUG_WARN("Error starting capture!\n");
/* Ensure we're really not capturing before releasing MDLs */
set_bit(CX18_F_S_STOPPING, &s->s_flags);
if (s->type == CX18_ENC_STREAM_TYPE_MPG)
cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, 1);
else
@ -622,6 +708,7 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);
cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
s->handle = CX18_INVALID_TASK_HANDLE;
clear_bit(CX18_F_S_STOPPING, &s->s_flags);
if (atomic_read(&cx->tot_capturing) == 0) {
set_bit(CX18_F_I_EOS, &cx->i_flags);
cx18_write_reg(cx, 5, CX18_DSP0_INTERRUPT_MASK);
@ -666,6 +753,7 @@ int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end)
if (atomic_read(&cx->tot_capturing) == 0)
return 0;
set_bit(CX18_F_S_STOPPING, &s->s_flags);
if (s->type == CX18_ENC_STREAM_TYPE_MPG)
cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, !gop_end);
else
@ -689,6 +777,7 @@ int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end)
cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
s->handle = CX18_INVALID_TASK_HANDLE;
clear_bit(CX18_F_S_STOPPING, &s->s_flags);
if (atomic_read(&cx->tot_capturing) > 0)
return 0;

5
drivers/media/video/cx18/cx18-streams.h
View file

@ -28,10 +28,13 @@ int cx18_streams_setup(struct cx18 *cx);
int cx18_streams_register(struct cx18 *cx);
void cx18_streams_cleanup(struct cx18 *cx, int unregister);
/* Capture related */
/* Related to submission of buffers to firmware */
void cx18_stream_load_fw_queue(struct cx18_stream *s);
struct cx18_queue *cx18_stream_put_buf_fw(struct cx18_stream *s,
struct cx18_buffer *buf);
void cx18_out_work_handler(struct work_struct *work);
/* Capture related */
int cx18_start_v4l2_encode_stream(struct cx18_stream *s);
int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end);