Re: Keene

[Antti Palosaari <crope@iki.fi>]

On 04/19/2013 10:12 AM, Hans Verkuil wrote:
> On Wed April 17 2013 21:45:24 Antti Palosaari wrote:
>> On 04/15/2013 09:55 AM, Hans Verkuil wrote:
>>> On Fri April 12 2013 02:11:41 Antti Palosaari wrote:
>>>> Hello Hans,
>>>> That device is working very, thank you for it. Anyhow, I noticed two things.
>>>>
>>>> 1) it does not start transmitting just after I plug it - I have to
>>>> retune it!
>>>> Output says it is tuned to 95.160000 MHz by default, but it is not.
>>>> After I issue retune, just to same channel it starts working.
>>>> $ v4l2-ctl -d /dev/radio0 --set-freq=95.16
>>>
>>> Can you try this patch:
>>>
>>
>> It does not resolve the problem. It is quite strange behavior. After I
>> install modules, and modules are unload, plug stick in first time, it
>> usually (not every-time) starts TX. But when I replug it without
>> unloading modules, it will never start TX. Tx is started always when I
>> set freq using v4l2-ctl.
>
> If you replace 'false' by 'true' in the cmd_main, does that make it work?
> I'm fairly certain that's the problem.

Nope, I replaces all 'false' with 'true' and problem remains. When 
modules were unload and device is plugged it starts TX. When I replug it 
doesn't start anymore.

I just added msleep(1000); just before keene_cmd_main() in .probe() and 
now it seems to work every-time. So it is definitely timing issue. I 
will try to find out some smallest suitable value for sleep and and sent 
patch.


>
>>
>> Possible timing issue?
>>
>>
>> Is there some flag API flag to tell start / stop device? For my mind
>> correct behavior is to stop TX and sleep when device is plugged/module
>> load. Something like set freq 0 when device is not active to tell user
>> it is not sending/receiving and must be tuned in order to operate.
>
> This is actually a core problem with the radio API: there is no clear
> way of turning the tuner or modulator on and off on command. With video
> you know that you can turn off the tuner if no filehandle is open. But
> with radio you do not have that luxury since audio can go through alsa
> or through an audio jack.
>
> One option is to use mute. Most radio receivers start off muted and you
> have to unmute first. This could be used as a signal for receivers to
> turn the tuner on/off. But for a modulator that's not an option: turning
> off the modulator means turning off the transmitter, and that's not what
> you want if you are, say, the presenter of a radio program and you want
> to quickly mute because you feel a sneeze coming :-)
>
> I think we need a specific API for this, but in the absence of one we should
> just leave the modulator enabled from the start.

yeah, that's just the issue I was wondering. Is there some reason 
frequency value could not be used? Defining frequency to 0MHz or -1MHz 
and Tx (maybe Rx too) is off?

Here is power consumption I measured:
26.5mA play=false (idle mode)
39.0mA Tx on 95.16 MHz

It wastes 12.5mA (from USB Vcc 5v) when Tx is enabled.

regards
Antti

>
> Regards,
>
> 	Hans
>
>>
>>
>> regards
>> Antti
>>
>>
>>
>>
>>
>>
>>> diff --git a/drivers/media/radio/radio-keene.c b/drivers/media/radio/radio-keene.c
>>> index 4c9ae76..99da3d4 100644
>>> --- a/drivers/media/radio/radio-keene.c
>>> +++ b/drivers/media/radio/radio-keene.c
>>> @@ -93,7 +93,7 @@ static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
>>>    	/* If bit 4 is set, then tune to the frequency.
>>>    	   If bit 3 is set, then unmute; if bit 2 is set, then mute.
>>>    	   If bit 1 is set, then enter idle mode; if bit 0 is set,
>>> -	   then enter transit mode.
>>> +	   then enter transmit mode.
>>>    	 */
>>>    	radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
>>>    							(freq ? 0x10 : 0);
>>> @@ -350,7 +350,6 @@ static int usb_keene_probe(struct usb_interface *intf,
>>>    	radio->pa = 118;
>>>    	radio->tx = 0x32;
>>>    	radio->stereo = true;
>>> -	radio->curfreq = 95.16 * FREQ_MUL;
>>>    	if (hdl->error) {
>>>    		retval = hdl->error;
>>>
>>> @@ -383,6 +382,8 @@ static int usb_keene_probe(struct usb_interface *intf,
>>>    	video_set_drvdata(&radio->vdev, radio);
>>>    	set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
>>>
>>> +	keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
>>> +
>>>    	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
>>>    	if (retval < 0) {
>>>    		dev_err(&intf->dev, "could not register video device\n");
>>>
>>>
>>>> 2) What is that log printing?
>>>> ALSA sound/usb/mixer.c:932 13:0: cannot get min/max values for control 2
>>>> (id 13)
>>>>
>>>>
>>>> usb 5-2: new full-speed USB device number 3 using ohci_hcd
>>>> usb 5-2: New USB device found, idVendor=046d, idProduct=0a0e
>>>> usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
>>>> usb 5-2: Product: B-LINK USB Audio
>>>> usb 5-2: Manufacturer: HOLTEK
>>>> ALSA sound/usb/mixer.c:932 13:0: cannot get min/max values for control 2
>>>> (id 13)
>>>> radio-keene 5-2:1.2: V4L2 device registered as radio0
>>>
>>> No idea, and I don't get that message either.
>>>
>>> Regards,
>>>
>>> 	Hans
>>>
>>>>
>>>>
>>>> $ v4l2-ctl -d /dev/radio0 --all -L
>>>> Driver Info (not using libv4l2):
>>>> 	Driver name   : radio-keene
>>>> 	Card type     : Keene FM Transmitter
>>>> 	Bus info      : usb-0000:00:13.0-2
>>>> 	Driver version: 3.9.0
>>>> 	Capabilities  : 0x800C0000
>>>> 		Modulator
>>>> 		Radio
>>>> Frequency: 1522560 (95.160000 MHz)
>>>> Modulator:
>>>> 	Name                 : FM
>>>> 	Capabilities         : 62.5 Hz stereo
>>>> 	Frequency range      : 76.0 MHz - 108.0 MHz
>>>> 	Subchannel modulation: stereo
>>>> Priority: 2
>>>>
>>>> User Controls
>>>>
>>>>                               mute (bool)   : default=0 value=0
>>>>
>>>> FM Radio Modulator Controls
>>>>
>>>>             audio_compression_gain (int)    : min=-15 max=18 step=3
>>>> default=0 value=0 flags=slider
>>>>                       pre_emphasis (menu)   : min=0 max=2 default=1 value=1
>>>> 				1: 50 Microseconds
>>>> 				2: 75 Microseconds
>>>>                   tune_power_level (int)    : min=84 max=118 step=1
>>>> default=118 value=118 flags=slider
>>>>
>>>>
>>>> regards
>>>> Antti
>>>>
>>>>
>>
>>
>>


-- 
http://palosaari.fi/