Re: [REVIEW PATCH 13/16] rtl2832_sdr: expose e4000 controls to user

[Antti Palosaari <crope@iki.fi>]

On 14.02.2014 17:02, Hans Verkuil wrote:
> On 02/11/2014 03:04 AM, Antti Palosaari wrote:
>> E4000 tuner driver provides now some controls. Expose those to
>> userland.
>>
>> Signed-off-by: Antti Palosaari <crope@iki.fi>
>> ---
>>   drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c | 10 ++++++----
>>   1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
>> index 9265424..18f8c56 100644
>> --- a/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
>> +++ b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
>> @@ -25,6 +25,7 @@
>>   #include "dvb_frontend.h"
>>   #include "rtl2832_sdr.h"
>>   #include "dvb_usb.h"
>> +#include "e4000.h"
>>
>>   #include <media/v4l2-device.h>
>>   #include <media/v4l2-ioctl.h>
>> @@ -1347,6 +1348,7 @@ struct dvb_frontend *rtl2832_sdr_attach(struct dvb_frontend *fe,
>>   	struct rtl2832_sdr_state *s;
>>   	const struct v4l2_ctrl_ops *ops = &rtl2832_sdr_ctrl_ops;
>>   	struct dvb_usb_device *d = i2c_get_adapdata(i2c);
>> +	struct v4l2_ctrl_handler *hdl;
>>
>>   	s = kzalloc(sizeof(struct rtl2832_sdr_state), GFP_KERNEL);
>>   	if (s == NULL) {
>> @@ -1386,10 +1388,10 @@ struct dvb_frontend *rtl2832_sdr_attach(struct dvb_frontend *fe,
>>   	/* Register controls */
>>   	switch (s->cfg->tuner) {
>>   	case RTL2832_TUNER_E4000:
>> -		v4l2_ctrl_handler_init(&s->hdl, 2);
>> -		s->bandwidth_auto = v4l2_ctrl_new_std(&s->hdl, ops, V4L2_CID_BANDWIDTH_AUTO, 0, 1, 1, 1);
>> -		s->bandwidth = v4l2_ctrl_new_std(&s->hdl, ops, V4L2_CID_BANDWIDTH, 4300000, 11000000, 100000, 4300000);
>> -		v4l2_ctrl_auto_cluster(2, &s->bandwidth_auto, 0, false);
>> +		hdl = e4000_get_ctrl_handler(fe);
>> +		v4l2_ctrl_handler_init(&s->hdl, 0);
>
> Use the same number as is used in e4000: 8.
>
> It's a hint of the number of controls that the handler will contain and it affects
> the number of buckets used for the hash table. Putting in a 0 will result in a single
> bucket which means that all controls end up in a single linked list. Changing it to
> 8 will result in two buckets, which performs a bit better.

OK. I was thinking that if I add handler to handler, I don't need to 
take into account how many controls the tuner handler has. Before you 
ask why there is 2 handlers merged, other having 0 controls, I left it 
that way I can add ADC controls later.

I am now going through that whole SDR patch serie and I will likely post 
fixed version tonight.

regards
Antti

-- 
http://palosaari.fi/