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>

1 files changed, 65 insertions, 12 deletions

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;
         }