On 07/17/2015 05:43 PM, Hans Verkuil wrote:
On 07/16/2015 09:04 AM, Antti Palosaari wrote:
HackRF SDR device has both receiver and transmitter. There is limitation
that receiver and transmitter cannot be used at the same time
(half-duplex operation). That patch implements transmitter support to
existing receiver only driver.
Cc: Hans Verkuil <hverkuil@xxxxxxxxx>
Signed-off-by: Antti Palosaari <crope@xxxxxx>
---
drivers/media/usb/hackrf/hackrf.c | 787 +++++++++++++++++++++++++++-----------
1 file changed, 572 insertions(+), 215 deletions(-)
@@ -611,8 +751,15 @@ static int hackrf_queue_setup(struct vb2_queue *vq,
unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[])
{
struct hackrf_dev *dev = vb2_get_drv_priv(vq);
+ struct usb_interface *intf = dev->intf;
+ int ret;
- dev_dbg(dev->dev, "nbuffers=%d\n", *nbuffers);
+ dev_dbg(&intf->dev, "nbuffers=%d\n", *nbuffers);
+
+ if (test_and_set_bit(QUEUE_SETUP, &dev->flags)) {
+ ret = -EBUSY;
+ goto err;
+ }
This doesn't work. The bit is only cleared when start_streaming fails or
stop_streaming is called. But the application can also call REQBUFS again
or just close the file handle, and then QUEUE_SETUP should also be cleared.
But why is this here in the first place? It doesn't seem to do anything
useful (except mess up the v4l2-compliance tests).
I've removed it and it now seems to work OK.
It is there to block simultaneous use of receiver and transmitter.
Device could operate only single mode at the time - receiving or
transmitting. Driver shares streaming buffers.
Any idea how I can easily implement correct blocking?
regards
Antti
--
http://palosaari.fi/
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