V4L/DVB (9801): cx18: Allow more than 63 capture buffers in rotation per stream

cx18: Allow more than 63 capture buffers in rotation per stream.  Implement
q_busy to hold buffers the firmware has for use.  q_free holds truly unused
buffers in a pool.  New buffers are given to the firmware as soon as the
firmware returns one, if there are any to give to the firmware.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

8 files changed, 113 insertions, 70 deletions

diff --git a/drivers/media/video/cx18/cx18-driver.h b/drivers/media/video/cx18/cx18-driver.h
index f88d82348293..4d56d07195b6 100644
--- a/drivers/media/video/cx18/cx18-driver.h
+++ b/drivers/media/video/cx18/cx18-driver.h
@@ -289,7 +289,8 @@ struct cx18_stream {
 
         /* Buffer Queues */
         struct cx18_queue q_free;       /* free buffers */
-        struct cx18_queue q_full;       /* full buffers */
+        struct cx18_queue q_busy;       /* busy buffers - in use by firmware */
+        struct cx18_queue q_full;       /* full buffers - data for user apps */
 
         /* DVB / Digital Transport */
         struct cx18_dvb dvb;
diff --git a/drivers/media/video/cx18/cx18-fileops.c b/drivers/media/video/cx18/cx18-fileops.c
index 504a1f9edec6..61192e62a80f 100644
--- a/drivers/media/video/cx18/cx18-fileops.c
+++ b/drivers/media/video/cx18/cx18-fileops.c
@@ -187,7 +187,7 @@ static struct cx18_buffer *cx18_get_buffer(struct cx18_stream *s, int non_block,
                                 while ((buf = cx18_dequeue(s_vbi, &s_vbi->q_full))) {
                                         /* byteswap and process VBI data */
 /*                                      cx18_process_vbi_data(cx, buf, s_vbi->dma_pts, s_vbi->type); */
-                                        cx18_enqueue(s_vbi, buf, &s_vbi->q_free);
+                                        cx18_stream_put_buf_fw(s_vbi, buf);
                                 }
                         }
                         buf = &cx->vbi.sliced_mpeg_buf;
@@ -361,15 +361,9 @@ static ssize_t cx18_read(struct cx18_stream *s, char __user *ubuf,
                                 tot_count - tot_written);
 
                 if (buf != &cx->vbi.sliced_mpeg_buf) {
-                        if (buf->readpos == buf->bytesused) {
-                                cx18_buf_sync_for_device(s, buf);
-                                cx18_enqueue(s, buf, &s->q_free);
-                                cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5,
-                                        s->handle,
-                                        (void __iomem *)&cx->scb->cpu_mdl[buf->id] -
-                                          cx->enc_mem,
-                                        1, buf->id, s->buf_size);
-                        } else
+                        if (buf->readpos == buf->bytesused)
+                                cx18_stream_put_buf_fw(s, buf);
+                        else
                                 cx18_push(s, buf, &s->q_full);
                 } else if (buf->readpos == buf->bytesused) {
                         int idx = cx->vbi.inserted_frame % CX18_VBI_FRAMES;
diff --git a/drivers/media/video/cx18/cx18-ioctl.c b/drivers/media/video/cx18/cx18-ioctl.c
index 8b2ec31b9421..ece799ec37aa 100644
--- a/drivers/media/video/cx18/cx18-ioctl.c
+++ b/drivers/media/video/cx18/cx18-ioctl.c
@@ -746,8 +746,7 @@ static int cx18_log_status(struct file *file, void *fh)
                         continue;
                 CX18_INFO("Stream %s: status 0x%04lx, %d%% of %d KiB (%d buffers) in use\n",
                           s->name, s->s_flags,
-                          (s->buffers - atomic_read(&s->q_free.buffers))
-                                * 100 / s->buffers,
+                          atomic_read(&s->q_full.buffers) * 100 / s->buffers,
                           (s->buffers * s->buf_size) / 1024, s->buffers);
         }
         CX18_INFO("Read MPEG/VBI: %lld/%lld bytes\n",
diff --git a/drivers/media/video/cx18/cx18-mailbox.c b/drivers/media/video/cx18/cx18-mailbox.c
index b013e817926a..9d8220539be8 100644
--- a/drivers/media/video/cx18/cx18-mailbox.c
+++ b/drivers/media/video/cx18/cx18-mailbox.c
@@ -189,16 +189,7 @@ static void epu_dma_done(struct cx18 *cx, struct cx18_epu_work_order *order)
                         dvb_dmx_swfilter(&s->dvb.demux, buf->buf,
                                          buf->bytesused);
 
-                        cx18_buf_sync_for_device(s, buf);
-                        cx18_enqueue(s, buf, &s->q_free);
-
-                        if (s->handle != CX18_INVALID_TASK_HANDLE &&
-                            test_bit(CX18_F_S_STREAMING, &s->s_flags))
-                                cx18_vapi(cx,
-                                       CX18_CPU_DE_SET_MDL, 5, s->handle,
-                                       (void __iomem *)
-                                       &cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
-                                       1, buf->id, s->buf_size);
+                        cx18_stream_put_buf_fw(s, buf);
                 } else
                         set_bit(CX18_F_B_NEED_BUF_SWAP, &buf->b_flags);
         }
diff --git a/drivers/media/video/cx18/cx18-queue.c b/drivers/media/video/cx18/cx18-queue.c
index fdfc83ee3d4e..40379d807cef 100644
--- a/drivers/media/video/cx18/cx18-queue.c
+++ b/drivers/media/video/cx18/cx18-queue.c
@@ -42,24 +42,32 @@ void cx18_queue_init(struct cx18_queue *q)
         q->bytesused = 0;
 }
 
-void _cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
-                   struct cx18_queue *q, int to_front)
+struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
+                                 struct cx18_queue *q, int to_front)
 {
-        /* clear the buffer if it is going to be enqueued to the free queue */
-        if (q == &s->q_free) {
+        /* clear the buffer if it is not to be enqueued to the full queue */
+        if (q != &s->q_full) {
                 buf->bytesused = 0;
                 buf->readpos = 0;
                 buf->b_flags = 0;
                 buf->skipped = 0;
         }
+
         mutex_lock(&s->qlock);
+
+        /* q_busy is restricted to 63 buffers to stay within firmware limits */
+        if (q == &s->q_busy && atomic_read(&q->buffers) >= 63)
+                q = &s->q_free;
+
         if (to_front)
                 list_add(&buf->list, &q->list); /* LIFO */
         else
                 list_add_tail(&buf->list, &q->list); /* FIFO */
-        atomic_inc(&q->buffers);
         q->bytesused += buf->bytesused - buf->readpos;
+        atomic_inc(&q->buffers);
+
         mutex_unlock(&s->qlock);
+        return q;
 }
 
 struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
@@ -70,9 +78,9 @@ struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
         if (!list_empty(&q->list)) {
                 buf = list_entry(q->list.next, struct cx18_buffer, list);
                 list_del_init(q->list.next);
-                atomic_dec(&q->buffers);
                 q->bytesused -= buf->bytesused - buf->readpos;
                 buf->skipped = 0;
+                atomic_dec(&q->buffers);
         }
         mutex_unlock(&s->qlock);
         return buf;
@@ -85,28 +93,30 @@ struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
         struct cx18_buffer *buf;
         struct cx18_buffer *ret = NULL;
         struct list_head *p, *t;
-        LIST_HEAD(r);
 
         mutex_lock(&s->qlock);
-        list_for_each_safe(p, t, &s->q_free.list) {
+        list_for_each_safe(p, t, &s->q_busy.list) {
                 buf = list_entry(p, struct cx18_buffer, list);
 
                 if (buf->id != id) {
                         buf->skipped++;
-                        if (buf->skipped >= atomic_read(&s->q_free.buffers)-1) {
+                        if (buf->skipped >= atomic_read(&s->q_busy.buffers)-1) {
                                 /* buffer must have fallen out of rotation */
-                                atomic_dec(&s->q_free.buffers);
-                                list_move_tail(&buf->list, &r);
                                 CX18_WARN("Skipped %s, buffer %d, %d "
                                           "times - it must have dropped out of "
                                           "rotation\n", s->name, buf->id,
                                           buf->skipped);
+                                /* move it to q_free */
+                                list_move_tail(&buf->list, &s->q_free.list);
+                                buf->bytesused = buf->readpos = buf->b_flags =
+                                        buf->skipped = 0;
+                                atomic_dec(&s->q_busy.buffers);
+                                atomic_inc(&s->q_free.buffers);
                         }
                         continue;
                 }
 
                 buf->bytesused = bytesused;
-                atomic_dec(&s->q_free.buffers);
                 if (s->type == CX18_ENC_STREAM_TYPE_TS) {
                         /*
                          * TS doesn't use q_full, but for sweeping up lost
@@ -116,28 +126,19 @@ struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
                          */
                         list_del_init(&buf->list);
                 } else {
-                        atomic_inc(&s->q_full.buffers);
-                        s->q_full.bytesused += buf->bytesused;
                         list_move_tail(&buf->list, &s->q_full.list);
+                        s->q_full.bytesused += buf->bytesused;
+                        atomic_inc(&s->q_full.buffers);
                 }
+                atomic_dec(&s->q_busy.buffers);
 
                 ret = buf;
                 break;
         }
-        mutex_unlock(&s->qlock);
 
-        /* Put lost buffers back into firmware transfer rotation */
-        while (!list_empty(&r)) {
-                buf = list_entry(r.next, struct cx18_buffer, list);
-                list_del_init(r.next);
-                cx18_enqueue(s, buf, &s->q_free);
-                cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
-                       (void __iomem *)&cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
-                       1, buf->id, s->buf_size);
-                CX18_INFO("Returning %s, buffer %d back to transfer rotation\n",
-                          s->name, buf->id);
-                /* and there was much rejoicing... */
-        }
+        /* Put more buffers into the transfer rotation from q_free, if we can */
+        cx18_stream_load_fw_queue_nolock(s);
+        mutex_unlock(&s->qlock);
         return ret;
 }
 
@@ -162,6 +163,7 @@ static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
 
 void cx18_flush_queues(struct cx18_stream *s)
 {
+        cx18_queue_flush(s, &s->q_busy);
         cx18_queue_flush(s, &s->q_full);
 }
 
diff --git a/drivers/media/video/cx18/cx18-queue.h b/drivers/media/video/cx18/cx18-queue.h
index d184e55ce624..456cec3bc28f 100644
--- a/drivers/media/video/cx18/cx18-queue.h
+++ b/drivers/media/video/cx18/cx18-queue.h
@@ -43,21 +43,21 @@ static inline void cx18_buf_sync_for_device(struct cx18_stream *s,
 void cx18_buf_swap(struct cx18_buffer *buf);
 
 /* cx18_queue utility functions */
-void _cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
-                   struct cx18_queue *q, int to_front);
+struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
+                                 struct cx18_queue *q, int to_front);
 
 static inline
-void cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
-                  struct cx18_queue *q)
+struct cx18_queue *cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
+                                struct cx18_queue *q)
 {
-        _cx18_enqueue(s, buf, q, 0); /* FIFO */
+        return _cx18_enqueue(s, buf, q, 0); /* FIFO */
 }
 
 static inline
-void cx18_push(struct cx18_stream *s, struct cx18_buffer *buf,
-               struct cx18_queue *q)
+struct cx18_queue *cx18_push(struct cx18_stream *s, struct cx18_buffer *buf,
+                             struct cx18_queue *q)
 {
-        _cx18_enqueue(s, buf, q, 1); /* LIFO */
+        return _cx18_enqueue(s, buf, q, 1); /* LIFO */
 }
 
 void cx18_queue_init(struct cx18_queue *q);
diff --git a/drivers/media/video/cx18/cx18-streams.c b/drivers/media/video/cx18/cx18-streams.c
index a1cf434f7975..6b0b7f751f20 100644
--- a/drivers/media/video/cx18/cx18-streams.c
+++ b/drivers/media/video/cx18/cx18-streams.c
@@ -127,16 +127,11 @@ static void cx18_stream_init(struct cx18 *cx, int type)
         s->buf_size = cx->stream_buf_size[type];
         if (s->buf_size)
                 s->buffers = max_size / s->buf_size;
-        if (s->buffers > 63) {
-                /* Each stream has a maximum of 63 buffers,
-                   ensure we do not exceed that. */
-                s->buffers = 63;
-                s->buf_size = (max_size / s->buffers) & ~0xfff;
-        }
         mutex_init(&s->qlock);
         init_waitqueue_head(&s->waitq);
         s->id = -1;
         cx18_queue_init(&s->q_free);
+        cx18_queue_init(&s->q_busy);
         cx18_queue_init(&s->q_full);
 }
 
@@ -401,11 +396,61 @@ 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)
+{
+        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_STREAMING, &s->s_flags))
+                return cx18_enqueue(s, buf, &s->q_free);
+
+        q = cx18_enqueue(s, buf, &s->q_busy);
+        if (q != &s->q_busy)
+                return q; /* The firmware has the max buffers it can handle */
+
+        cx18_buf_sync_for_device(s, buf);
+        cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
+                  (void __iomem *) &cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
+                  1, buf->id, s->buf_size);
+        return q;
+}
+
+/* Must hold s->qlock when calling */
+void cx18_stream_load_fw_queue_nolock(struct cx18_stream *s)
+{
+        struct cx18_buffer *buf;
+        struct cx18 *cx = s->cx;
+
+        /* Move from q_free to q_busy notifying the firmware: 63 buf limit */
+        while (s->handle != CX18_INVALID_TASK_HANDLE &&
+               test_bit(CX18_F_S_STREAMING, &s->s_flags) &&
+               atomic_read(&s->q_busy.buffers) < 63 &&
+               !list_empty(&s->q_free.list)) {
+
+                /* Move from q_free to q_busy */
+                buf = list_entry(s->q_free.list.next, struct cx18_buffer, list);
+                list_move_tail(&buf->list, &s->q_busy.list);
+                buf->bytesused = buf->readpos = buf->b_flags = buf->skipped = 0;
+                atomic_dec(&s->q_free.buffers);
+                atomic_inc(&s->q_busy.buffers);
+
+                /* Notify firmware */
+                cx18_buf_sync_for_device(s, buf);
+                cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
+                  (void __iomem *) &cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
+                  1, buf->id, s->buf_size);
+        }
+}
+
 int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
 {
         u32 data[MAX_MB_ARGUMENTS];
         struct cx18 *cx = s->cx;
         struct list_head *p;
+        struct cx18_buffer *buf;
         int ts = 0;
         int captype = 0;
 
@@ -488,16 +533,18 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
                 (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][0] - cx->enc_mem,
                 (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][1] - cx->enc_mem);
 
+        /* Init all the cpu_mdls for this stream */
+        cx18_flush_queues(s);
+        mutex_lock(&s->qlock);
         list_for_each(p, &s->q_free.list) {
-                struct cx18_buffer *buf = list_entry(p, struct cx18_buffer, list);
-
+                buf = list_entry(p, struct cx18_buffer, list);
                 cx18_writel(cx, buf->dma_handle,
                                         &cx->scb->cpu_mdl[buf->id].paddr);
                 cx18_writel(cx, s->buf_size, &cx->scb->cpu_mdl[buf->id].length);
-                cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
-                        (void __iomem *)&cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
-                        1, buf->id, s->buf_size);
         }
+        cx18_stream_load_fw_queue_nolock(s);
+        mutex_unlock(&s->qlock);
+
         /* begin_capture */
         if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) {
                 CX18_DEBUG_WARN("Error starting capture!\n");
@@ -506,9 +553,15 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
                         cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, 1);
                 else
                         cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);
+                clear_bit(CX18_F_S_STREAMING, &s->s_flags);
+                /* FIXME - CX18_F_S_STREAMOFF as well? */
                 cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);
                 cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
-                /* FIXME - clean-up DSP0_INT mask, i_flags, s_flags, etc. */
+                s->handle = CX18_INVALID_TASK_HANDLE;
+                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);
+                }
                 return -EINVAL;
         }
 
diff --git a/drivers/media/video/cx18/cx18-streams.h b/drivers/media/video/cx18/cx18-streams.h
index 7218b15045bf..635d34b75ab1 100644
--- a/drivers/media/video/cx18/cx18-streams.h
+++ b/drivers/media/video/cx18/cx18-streams.h
@@ -29,6 +29,9 @@ int cx18_streams_register(struct cx18 *cx);
 void cx18_streams_cleanup(struct cx18 *cx, int unregister);
 
 /* Capture related */
+void cx18_stream_load_fw_queue_nolock(struct cx18_stream *s);
+struct cx18_queue *cx18_stream_put_buf_fw(struct cx18_stream *s,
+                                          struct cx18_buffer *buf);
 int cx18_start_v4l2_encode_stream(struct cx18_stream *s);
 int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end);