Hans,
A few questions:
1. The handle member in struct cx18_stream is initialized and cleared
to 0xffffffff to indicated non-use. BTW, the CX23418 appears to begin
assigning task handles starting with 0. So what is
cx18_streams:cx18_find_handle() really trying to do? Find the first
used handle or first unused handle?
u32 cx18_find_handle(struct cx18 *cx)
{
int i;
/* find first available handle to be used for global settings */
for (i = 0; i < CX18_MAX_STREAMS; i++) {
struct cx18_stream *s = &cx->streams[i];
if (s->v4l2dev && s->handle)
return s->handle;
}
return 0;
}
The above code will reject handle 0 and likely return either 0xffffffff
or 1 in the most common cases.
2. The CX23418 appears to reuse handles:
Aug 23 11:01:02 morgan kernel: cx18-0 info: Start feed: pid = 0x31 index = 0
Aug 23 11:01:02 morgan kernel: cx18-0 info: Starting Transport DMA
Aug 23 11:01:02 morgan kernel: cx18-0 info: Start encoder stream TS
Aug 23 11:01:02 morgan kernel: cx18-0 info: Stream TS task given handle 0 by
CX23418
[...]
Aug 23 11:01:09 morgan kernel: cx18-0 info: Stopping Transport DMA
Aug 23 11:01:09 morgan kernel: cx18-0 info: Stop Capture
Aug 23 11:01:09 morgan kernel: cx180 irq: SW1: 10000 SW2: 0 HW2: 0
Aug 23 11:01:09 morgan kernel: cx180 irq: queue_get_buf_irq enter
Aug 23 11:01:09 morgan kernel: cx180 irq: queue_get_buf_irq normal exit
Aug 23 11:01:09 morgan kernel: cx18-0 info: Stop Capture mbox command sent
Aug 23 11:01:09 morgan kernel: cx18-0 info: Destroy task mbox command sent
Aug 23 11:01:09 morgan kernel: cx18-0 info: DSP0 interrupt mask altered
Aug 23 11:26:22 morgan kernel: cx18-0 info: Start encoder stream encoder MPEG
Aug 23 11:26:22 morgan kernel: cx18-0 info: Stream encoder MPEG task given
handle 0 by CX23418
So without asking the CX23418 to release the MDLs at the end of a
capture, the CX23418 can later return a data buffer with a buffer id in
the wrong range for a stream type. cx18_queue_get_buf_irq() will gripe
when this happens and the data in that buffer will be wrongly dropped.
In cx23418.h, CX18_CPU_DE_ReleaseMDL is commented out. Is there a
problem with it, or is it OK to uncomment and use?
Regards,
Andy
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