tea575x: fix HW seek

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 <[email protected]>

sound/i2c/other/tea575x-tuner.c +1 -1

@@ -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;

Quoted 27 lines · 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 <[email protected]>

sound/i2c/other/tea575x-tuner.c +1 -1

@@ -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;
 }
 

sound/i2c/other/tea575x-tuner.c static unsigned int snd_tea575x_read(struct · line 128

Quoted 6 lines

sound/i2c/other/tea575x-tuner.c +6 -0

+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:

(quoted diff) +0 -0

b/sound/i2c/other/tea575x-tuner.c index 474bb81..02da22f 100644

sound/i2c/other/tea575x-tuner.c +11 -8

@@ -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 */

sound/i2c/other/tea575x-tuner.c +2 -2

 			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

Quoted 28 lines · Hans Verkuil

Quoted 27 lines · 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 <[email protected]>

sound/i2c/other/tea575x-tuner.c +1 -1

@@ -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;
 }
 

Quoted 10 lines

sound/i2c/other/tea575x-tuner.c static unsigned int snd_tea575x_read(struct · line 128

Quoted 6 lines

sound/i2c/other/tea575x-tuner.c +6 -0

+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.

The device returns zero frequency when the scan fails to find a frequency. This is not an error, just an indication that "nothing" is tuned. So maybe we can return some bogus frequency in vidioc_g_frequency (like FREQ_LO) in this case (don't know if -EBUSY will break anything). But HW seek should get the real one (i.e. zero when it's there).

Quoted 41 lines · On Wednesday, February 22, 2012 09:35:28 Ondrej Zary wrote:

Quoted 29 lines · Hans Verkuil

Quoted 28 lines · 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 <[email protected]>

sound/i2c/other/tea575x-tuner.c +1 -1

@@ -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;
 }
 

Quoted 10 lines

sound/i2c/other/tea575x-tuner.c static unsigned int snd_tea575x_read(struct · line 128

Quoted 6 lines

sound/i2c/other/tea575x-tuner.c +6 -0

+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.

Quoted 5 lines

The device returns zero frequency when the scan fails to find a frequency. This is not an error, just an indication that "nothing" is tuned. So maybe we can return some bogus frequency in vidioc_g_frequency (like FREQ_LO) in this case (don't know if -EBUSY will break anything). But HW seek should get the real one (i.e. zero when it's there).

How about the following patch? vidioc_g_frequency just returns the last set frequency and the hw_seek restores the original frequency if it can't find another channel.

Also note that the check for < 50 kHz in hw_seek actually checked for < 500 kHz. I've fixed that, but I can't test it.

Do you also know what happens at the boundaries of the frequency range? Does it wrap around, or do you get a timeout?

Regards,

Hans

(quoted diff) +0 -0

b/sound/i2c/other/tea575x-tuner.c index 474bb81..1bdf1f3 100644

sound/i2c/other/tea575x-tuner.c +16 -15

@@ -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 u32 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 freq;
 
 	/* freq *= 12.5 */
 	freq *= 125;

@@ -138,7 +136,7 @@ static void snd_tea575x_get_freq(struct snd_tea575x
 *tea) else
 		freq -= TEA575X_FMIF;
 
-	tea->freq = clamp(freq * 16, FREQ_LO, FREQ_HI); /* from kHz */
+	return clamp(freq * 16, FREQ_LO, FREQ_HI); /* from kHz */
 }
 
 static void snd_tea575x_set_freq(struct snd_tea575x *tea)

@@ -224,8 +222,6 @@ static int vidioc_g_frequency(struct file *file, void
 *priv, if (f->tuner != 0)
 		return -EINVAL;
 	f->type = V4L2_TUNER_RADIO;
-	if (!tea->cannot_read_data)
-		snd_tea575x_get_freq(tea);
 	f->frequency = tea->freq;
 	return 0;
 }

@@ -248,14 +244,12 @@ static int vidioc_s_hw_freq_seek(struct file *file,
 void *fh, struct v4l2_hw_freq_seek *a)
 {
 	struct snd_tea575x *tea = video_drvdata(file);
-	int i, old_freq;
 	unsigned long timeout;
+	int i;
 
 	if (tea->cannot_read_data)
 		return -ENOTTY;
 
-	snd_tea575x_get_freq(tea);
-	old_freq = tea->freq;
 	/* clear the frequency, HW will fill it in */
 	tea->val &= ~TEA575X_BIT_FREQ_MASK;
 	tea->val |= TEA575X_BIT_SEARCH;

@@ -271,26 +265,33 @@ static int vidioc_s_hw_freq_seek(struct file *file,
 void *fh, if (schedule_timeout_interruptible(msecs_to_jiffies(10))) {
 			/* some signal arrived, stop search */
 			tea->val &= ~TEA575X_BIT_SEARCH;
-			snd_tea575x_write(tea, tea->val);
+			snd_tea575x_set_freq(tea);
 			return -ERESTARTSYS;
 		}
 		if (!(snd_tea575x_read(tea) & TEA575X_BIT_SEARCH)) {
+			u32 freq;
+
 			/* 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 */
+				freq = snd_tea575x_get_freq(tea);
+				if (freq) /* available */
 					break;
 			}
+			if (freq == 0) /* shouldn't happen */
+				break;
 			/* if we moved by less than 50 kHz, continue seeking */
-			if (abs(old_freq - tea->freq) < 16 * 500) {
+			if (abs(tea->freq - freq) < 16 * 50) {
 				snd_tea575x_write(tea, tea->val);
 				continue;
 			}
+			tea->freq = freq;
 			tea->val &= ~TEA575X_BIT_SEARCH;
 			return 0;
 		}
 	}
+	tea->val &= ~TEA575X_BIT_SEARCH;
+	snd_tea575x_set_freq(tea);
 	return -ETIMEDOUT;
 }

Quoted 48 lines · On Friday 24 February 2012 10:00:01 Hans Verkuil wrote:

Quoted 41 lines · On Wednesday, February 22, 2012 09:35:28 Ondrej Zary wrote:

Quoted 29 lines · Hans Verkuil

Quoted 28 lines · 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 <[email protected]>

sound/i2c/other/tea575x-tuner.c +1 -1

@@ -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;
 }
 

Quoted 10 lines

sound/i2c/other/tea575x-tuner.c static unsigned int snd_tea575x_read(struct · line 128

Quoted 6 lines

sound/i2c/other/tea575x-tuner.c +6 -0

+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.

Quoted 5 lines

The device returns zero frequency when the scan fails to find a frequency. This is not an error, just an indication that "nothing" is tuned. So maybe we can return some bogus frequency in vidioc_g_frequency (like FREQ_LO) in this case (don't know if -EBUSY will break anything). But HW seek should get the real one (i.e. zero when it's there).

Quoted 3 lines

How about the following patch? vidioc_g_frequency just returns the last set frequency and the hw_seek restores the original frequency if it can't find another channel.

Seems to work. That's probably the right thing to do.

Quoted 2 lines

Also note that the check for < 50 kHz in hw_seek actually checked for < 500 kHz. I've fixed that, but I can't test it.

Thanks. It finds more stations now. To improve reliability, an additional check should be added - the seek sometimes stop at the same station, just a bit more than 50kHz of the original frequency, often in wrong direction. Something like this:

sound/i2c/other/tea575x-tuner.c +7 -2

@@ -280,8 +280,13 @@ static int vidioc_s_hw_freq_seek(struct file *file, void 
 *fh,
                        }
                        if (freq == 0) /* shouldn't happen */
                                break;
-                       /* if we moved by less than 50 kHz, continue seeking 
 */
-                       if (abs(tea->freq - freq) < 16 * 50) {
+                       /*
+                        * if we moved by less than 50 kHz, or in the wrong
+                        * direction, continue seeking
+                        */
+                       if (abs(tea->freq - freq) < 16 * 50 ||
+                           (a->seek_upward && freq < tea->freq) ||
+                           (!a->seek_upward && freq > tea->freq)) {
                                snd_tea575x_write(tea, tea->val);

                                continue;
                        }

Quoted 4 lines

Do you also know what happens at the boundaries of the frequency range? Does it wrap around, or do you get a timeout?

No wraparound, it times out so the original frequency is restored. I wonder if -ETIMEDOUT is correct here.

Quoted 78 lines · On Sunday, February 26, 2012 22:02:51 Ondrej Zary wrote:

Quoted 50 lines · On Friday 24 February 2012 10:00:01 Hans Verkuil wrote:

Quoted 42 lines · On Wednesday, February 22, 2012 09:35:28 Ondrej Zary wrote:

Quoted 29 lines · Hans Verkuil

Quoted 28 lines · 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 <[email protected]>

sound/i2c/other/tea575x-tuner.c +1 -1

@@ -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;
 }
 

Quoted 11 lines

sound/i2c/other/tea575x-tuner.c static unsigned int snd_tea575x_read(struct · line 128

Quoted 6 lines

sound/i2c/other/tea575x-tuner.c +6 -0

+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.

Quoted 6 lines

The device returns zero frequency when the scan fails to find a frequency. This is not an error, just an indication that "nothing" is tuned. So maybe we can return some bogus frequency in vidioc_g_frequency (like FREQ_LO) in this case (don't know if -EBUSY will break anything). But HW seek should get the real one (i.e. zero when it's there).

Quoted 3 lines

How about the following patch? vidioc_g_frequency just returns the last set frequency and the hw_seek restores the original frequency if it can't find another channel.

Seems to work. That's probably the right thing to do.

Quoted 2 lines

Also note that the check for < 50 kHz in hw_seek actually checked for < 500 kHz. I've fixed that, but I can't test it.

Thanks. It finds more stations now. To improve reliability, an additional check should be added - the seek sometimes stop at the same station, just a bit more than 50kHz of the original frequency, often in wrong direction. Something like this:

sound/i2c/other/tea575x-tuner.c +0 -1

@@ -280,8 +280,13 @@ static int vidioc_s_hw_freq_seek(struct file *file,
 void *fh,
                        }
                        if (freq == 0) /* shouldn't happen */
                                break;
-                       /* if we moved by less than 50 kHz, continue

seeking */

sound/i2c/other/tea575x-tuner.c +2 -1

-                       if (abs(tea->freq - freq) < 16 * 50) {
+                       /*
+                        * if we moved by less than 50 kHz, or in the

wrong + * direction, continue seeking

sound/i2c/other/tea575x-tuner.c

Quoted 7 lines

sound/i2c/other/tea575x-tuner.c +4 -0

+                        */
+                       if (abs(tea->freq - freq) < 16 * 50 ||
+                           (a->seek_upward && freq < tea->freq) ||
+                           (!a->seek_upward && freq > tea->freq)) {
                                snd_tea575x_write(tea, tea->val);
                                continue;
                        }

Added to the patch series.

Quoted 5 lines

Quoted 2 lines

Do you also know what happens at the boundaries of the frequency range? Does it wrap around, or do you get a timeout?

No wraparound, it times out so the original frequency is restored. I wonder if -ETIMEDOUT is correct here.

That's actually wrong, it should be -EAGAIN according to the spec.

I'm now returning -EINVAL if the wrap_around value is not supported and I've updated the spec to mention that possibility explicitly.

My latest tree is here:

The following changes since commit
a3db60bcf7671cc011ab4f848cbc40ff7ab52c1e:

[media] xc5000: declare firmware configuration structures as static const
(2012-02-14 17:22:46 -0200)

are available in the git repository at:
git://linuxtv.org/hverkuil/media_tree.git radio-pci

Hans Verkuil (4):
tea575x-tuner: update to latest V4L2 framework requirements.
tea575x: fix HW seek
radio-maxiradio: use the tea575x framework.
V4L2 Spec: return -EINVAL on unsupported wrap_around value.

 .../DocBook/media/v4l/vidioc-s-hw-freq-seek.xml    |    6 +-
 drivers/media/radio/Kconfig                        |    2 +-
 drivers/media/radio/radio-maxiradio.c              |  379
++++---------------- drivers/media/radio/radio-sf16fmr2.c               |  
61 +++-
 include/sound/tea575x-tuner.h                      |    6 +-
 sound/i2c/other/tea575x-tuner.c                    |  169 ++++++---
 sound/pci/es1968.c                                 |   15 +
 sound/pci/fm801.c                                  |   20 +-
 8 files changed, 273 insertions(+), 385 deletions(-)

If there are no more comments, then I want to make a pull request for this by the end of the week.