Em Fri, 22 Mar 2013 14:50:28 -0400
Devin Heitmueller <dheitmueller@xxxxxxxxxxxxxx> escreveu:
> On Fri, Mar 22, 2013 at 12:38 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> > It works fine with qv4l2, but there is still a bug causing tvtime to fail.
> > That's caused by commit e58071f024aa337b7ce41682578b33895b024f8b, applied
> > August last year, that broke g_tuner: after that 'signal' would always be 0
> > and tvtime expects signal to be non-zero for a valid frequency.
I don't think so: tvtime has a way to either honor signal or to ignore it
via GUI. As there are tuners that can't provide any signal level, I suspect
that this is the reason why it was coded this way.
> > The signal
> > field is set by the au8522, but g_tuner is only called for the tuner (well,
> > also for au8522 but since the i2c gate is set for the tuner that won't do
> > anything).
As far as I remember, there are a few drivers or boards whose signal
information is provided by the bridge and not by the tuner. I think
that this still works. For example:
drivers/media/pci/bt8xx/bttv-driver.c:static int bttv_g_tuner(struct file *file, void *priv,
drivers/media/pci/bt8xx/bttv-driver.c- struct v4l2_tuner *t)
drivers/media/pci/bt8xx/bttv-driver.c-{
drivers/media/pci/bt8xx/bttv-driver.c- struct bttv_fh *fh = priv;
drivers/media/pci/bt8xx/bttv-driver.c- struct bttv *btv = fh->btv;
drivers/media/pci/bt8xx/bttv-driver.c-
drivers/media/pci/bt8xx/bttv-driver.c- if (0 != t->index)
drivers/media/pci/bt8xx/bttv-driver.c- return -EINVAL;
drivers/media/pci/bt8xx/bttv-driver.c-
drivers/media/pci/bt8xx/bttv-driver.c- t->rxsubchans = V4L2_TUNER_SUB_MONO;
drivers/media/pci/bt8xx/bttv-driver.c- t->capability = V4L2_TUNER_CAP_NORM;
drivers/media/pci/bt8xx/bttv-driver.c- bttv_call_all(btv, tuner, g_tuner, t);
drivers/media/pci/bt8xx/bttv-driver.c- strcpy(t->name, "Television");
drivers/media/pci/bt8xx/bttv-driver.c- t->type = V4L2_TUNER_ANALOG_TV;
drivers/media/pci/bt8xx/bttv-driver.c- if (btread(BT848_DSTATUS)&BT848_DSTATUS_HLOC)
drivers/media/pci/bt8xx/bttv-driver.c- t->signal = 0xffff;
drivers/media/pci/bt8xx/bttv-driver.c-
drivers/media/pci/bt8xx/bttv-driver.c- if (btv->audio_mode_gpio)
drivers/media/pci/bt8xx/bttv-driver.c- btv->audio_mode_gpio(btv, t, 0);
drivers/media/pci/bt8xx/bttv-driver.c-
drivers/media/pci/bt8xx/bttv-driver.c- return 0;
changeset e58071f024aa337b7ce41682578b33895b024f8b doesn't affect it.
> Wait, are you saying that the G_TUNER call is no longer being routed
> to the au8522 driver? The signal level has always been set to a
> nonzero value by au8522 if a signal is present, and thus the state of
> the i2c gate isn't relevant.
The logic there seems to need a proper I2C gate setting:
drivers/media/dvb-frontends/au8522_decoder.c:static int au8522_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
drivers/media/dvb-frontends/au8522_decoder.c-{
drivers/media/dvb-frontends/au8522_decoder.c- int val = 0;
drivers/media/dvb-frontends/au8522_decoder.c- struct au8522_state *state = to_state(sd);
drivers/media/dvb-frontends/au8522_decoder.c- u8 lock_status;
drivers/media/dvb-frontends/au8522_decoder.c-
drivers/media/dvb-frontends/au8522_decoder.c- /* Interrogate the decoder to see if we are getting a real signal */
drivers/media/dvb-frontends/au8522_decoder.c- lock_status = au8522_readreg(state, 0x00);
drivers/media/dvb-frontends/au8522_decoder.c- if (lock_status == 0xa2)
drivers/media/dvb-frontends/au8522_decoder.c- vt->signal = 0xffff;
drivers/media/dvb-frontends/au8522_decoder.c- else
drivers/media/dvb-frontends/au8522_decoder.c- vt->signal = 0x00;
drivers/media/dvb-frontends/au8522_decoder.c-
drivers/media/dvb-frontends/au8522_decoder.c- vt->capability |=
drivers/media/dvb-frontends/au8522_decoder.c- V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_LANG1 |
drivers/media/dvb-frontends/au8522_decoder.c- V4L2_TUNER_CAP_LANG2 | V4L2_TUNER_CAP_SAP;
drivers/media/dvb-frontends/au8522_decoder.c-
drivers/media/dvb-frontends/au8522_decoder.c- val = V4L2_TUNER_SUB_MONO;
drivers/media/dvb-frontends/au8522_decoder.c- vt->rxsubchans = val;
drivers/media/dvb-frontends/au8522_decoder.c- vt->audmode = V4L2_TUNER_MODE_STEREO;
drivers/media/dvb-frontends/au8522_decoder.c- return 0;
As if the i2c gate is on a wrong state, au8522_readreg() won't
work anymore.
> This is because the xc5000 driver didn't
> actually have implemented a call to return the signal level.
>
> If what you're saying is true, then the behavior of the framework
> itself changed, and who knows what else is broken.
I don't think that the framework behavior has changed with that
regards.
Anyway, until we have this issue fixed, I'll mark this patch
as "changes requested".
Regards,
Mauro
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