On Saturday, February 18, 2012 17:45:45 Ondrej Zary wrote:
> Fix HW seek in TEA575x to work properly:
> - a delay must be present after search start and before first register read
> or the seek does weird things
> - when the search stops, the new frequency is not available immediately, we
> must wait until it appears in the register (fortunately, we can clear the
> frequency bits when starting the search as it starts at the frequency
> currently set, not from the value written)
> - sometimes, seek remains on the current frequency (or moves only a little),
> so repeat it until it moves by at least 50 kHz
>
> Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
>
> --- a/sound/i2c/other/tea575x-tuner.c
> +++ b/sound/i2c/other/tea575x-tuner.c
> @@ -89,7 +89,7 @@ static void snd_tea575x_write(struct snd_tea575x *tea, unsigned int val)
> tea->ops->set_pins(tea, 0);
> }
>
> -static unsigned int snd_tea575x_read(struct snd_tea575x *tea)
> +static u32 snd_tea575x_read(struct snd_tea575x *tea)
> {
> u16 l, rdata;
> u32 data = 0;
> @@ -120,6 +120,27 @@ static unsigned int snd_tea575x_read(struct snd_tea575x *tea)
> return data;
> }
>
> +static void snd_tea575x_get_freq(struct snd_tea575x *tea)
> +{
> + u32 freq = snd_tea575x_read(tea) & TEA575X_BIT_FREQ_MASK;
> +
> + if (freq == 0) {
> + tea->freq = 0;
Wouldn't it be better to return -EBUSY in this case? VIDIOC_G_FREQUENCY
should not return frequencies outside the valid frequency range. In this case
returning -EBUSY seems to make more sense to me.
I'm proposing adding this patch:
diff --git a/sound/i2c/other/tea575x-tuner.c b/sound/i2c/other/tea575x-tuner.c
index 474bb81..02da22f 100644
--- a/sound/i2c/other/tea575x-tuner.c
+++ b/sound/i2c/other/tea575x-tuner.c
@@ -120,14 +120,12 @@ static u32 snd_tea575x_read(struct snd_tea575x *tea)
return data;
}
-static void snd_tea575x_get_freq(struct snd_tea575x *tea)
+static int snd_tea575x_get_freq(struct snd_tea575x *tea)
{
u32 freq = snd_tea575x_read(tea) & TEA575X_BIT_FREQ_MASK;
- if (freq == 0) {
- tea->freq = 0;
- return;
- }
+ if (freq == 0)
+ return -EBUSY;
/* freq *= 12.5 */
freq *= 125;
@@ -139,6 +137,7 @@ static void snd_tea575x_get_freq(struct snd_tea575x *tea)
freq -= TEA575X_FMIF;
tea->freq = clamp(freq * 16, FREQ_LO, FREQ_HI); /* from kHz */
+ return 0;
}
static void snd_tea575x_set_freq(struct snd_tea575x *tea)
@@ -220,14 +219,15 @@ static int vidioc_g_frequency(struct file *file, void *priv,
struct v4l2_frequency *f)
{
struct snd_tea575x *tea = video_drvdata(file);
+ int ret = 0;
if (f->tuner != 0)
return -EINVAL;
f->type = V4L2_TUNER_RADIO;
if (!tea->cannot_read_data)
- snd_tea575x_get_freq(tea);
+ ret = snd_tea575x_get_freq(tea);
f->frequency = tea->freq;
- return 0;
+ return ret;
}
static int vidioc_s_frequency(struct file *file, void *priv,
@@ -250,11 +250,14 @@ static int vidioc_s_hw_freq_seek(struct file *file, void *fh,
struct snd_tea575x *tea = video_drvdata(file);
int i, old_freq;
unsigned long timeout;
+ int ret;
if (tea->cannot_read_data)
return -ENOTTY;
- snd_tea575x_get_freq(tea);
+ ret = snd_tea575x_get_freq(tea);
+ if (ret)
+ return ret;
old_freq = tea->freq;
/* clear the frequency, HW will fill it in */
tea->val &= ~TEA575X_BIT_FREQ_MASK;
@@ -278,8 +281,8 @@ static int vidioc_s_hw_freq_seek(struct file *file, void *fh,
/* Found a frequency, wait until it can be read */
for (i = 0; i < 100; i++) {
msleep(10);
- snd_tea575x_get_freq(tea);
- if (tea->freq != 0) /* available */
+ ret = snd_tea575x_get_freq(tea);
+ if (ret == 0) /* available */
break;
}
/* if we moved by less than 50 kHz, continue seeking */
If you are OK with this, then I'll put everything together and make a final
pull request.
Regards,
Hans
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