[PATCH 1/3] media: rc: nuvoton: Tweak the interrupt enabling dance

[PATCH 1/3] media: rc: nuvoton: Tweak the interrupt enabling dance

[Michał Winiarski]

It appears that we need to enable CIR device before attempting to touch
some of the registers. Previously, this was not a big issue, since we
were rarely seeing nvt_close() getting called.

Unfortunately, since:
cb84343fced1 ("media: lirc: do not call close() or open() on unregistered devices")

The initial open() during probe from rc_setup_rx_device() is no longer
successful, which means that userspace clients will actually end up
calling nvt_open()/nvt_close().
And since nvt_open() is broken, the device doesn't seem to work as
expected.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199597
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Sean Young <sean@mess.org>
---
 drivers/media/rc/nuvoton-cir.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
index 5e1d866a61a5..ce8949b6549d 100644
--- a/drivers/media/rc/nuvoton-cir.c
+++ b/drivers/media/rc/nuvoton-cir.c
@@ -922,6 +922,9 @@ static int nvt_open(struct rc_dev *dev)
 	struct nvt_dev *nvt = dev->priv;
 	unsigned long flags;
 
+	/* enable the CIR logical device */
+	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
+
 	spin_lock_irqsave(&nvt->lock, flags);
 
 	/* set function enable flags */
@@ -937,9 +940,6 @@ static int nvt_open(struct rc_dev *dev)
 
 	spin_unlock_irqrestore(&nvt->lock, flags);
 
-	/* enable the CIR logical device */
-	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
-
 	return 0;
 }
 
-- 
2.17.0

[PATCH 2/3] media: rc: nuvoton: Keep track of users on CIR enable/disable

[Michał Winiarski]

Core rc keeps track of the users - let's use it to tweak the code and
use the common code path on suspend/resume.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Sean Young <sean@mess.org>
---
 drivers/media/rc/nuvoton-cir.c | 82 +++++++++++++++-------------------
 1 file changed, 36 insertions(+), 46 deletions(-)

diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
index ce8949b6549d..eebd6fef5602 100644
--- a/drivers/media/rc/nuvoton-cir.c
+++ b/drivers/media/rc/nuvoton-cir.c
@@ -543,27 +543,9 @@ static void nvt_cir_regs_init(struct nvt_dev *nvt)
 	nvt_cir_reg_write(nvt, CIR_FIFOCON_TX_TRIGGER_LEV |
 			  CIR_FIFOCON_RX_TRIGGER_LEV, CIR_FIFOCON);
 
-	/*
-	 * Enable TX and RX, specify carrier on = low, off = high, and set
-	 * sample period (currently 50us)
-	 */
-	nvt_cir_reg_write(nvt,
-			  CIR_IRCON_TXEN | CIR_IRCON_RXEN |
-			  CIR_IRCON_RXINV | CIR_IRCON_SAMPLE_PERIOD_SEL,
-			  CIR_IRCON);
-
 	/* clear hardware rx and tx fifos */
 	nvt_clear_cir_fifo(nvt);
 	nvt_clear_tx_fifo(nvt);
-
-	/* clear any and all stray interrupts */
-	nvt_cir_reg_write(nvt, 0xff, CIR_IRSTS);
-
-	/* and finally, enable interrupts */
-	nvt_set_cir_iren(nvt);
-
-	/* enable the CIR logical device */
-	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
 }
 
 static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
@@ -892,6 +874,32 @@ static irqreturn_t nvt_cir_isr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static void nvt_enable_cir(struct nvt_dev *nvt)
+{
+	unsigned long flags;
+
+	/* enable the CIR logical device */
+	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
+
+	spin_lock_irqsave(&nvt->lock, flags);
+
+	/*
+	 * Enable TX and RX, specify carrier on = low, off = high, and set
+	 * sample period (currently 50us)
+	 */
+	nvt_cir_reg_write(nvt, CIR_IRCON_TXEN | CIR_IRCON_RXEN |
+			  CIR_IRCON_RXINV | CIR_IRCON_SAMPLE_PERIOD_SEL,
+			  CIR_IRCON);
+
+	/* clear all pending interrupts */
+	nvt_cir_reg_write(nvt, 0xff, CIR_IRSTS);
+
+	/* enable interrupts */
+	nvt_set_cir_iren(nvt);
+
+	spin_unlock_irqrestore(&nvt->lock, flags);
+}
+
 static void nvt_disable_cir(struct nvt_dev *nvt)
 {
 	unsigned long flags;
@@ -920,25 +928,8 @@ static void nvt_disable_cir(struct nvt_dev *nvt)
 static int nvt_open(struct rc_dev *dev)
 {
 	struct nvt_dev *nvt = dev->priv;
-	unsigned long flags;
 
-	/* enable the CIR logical device */
-	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
-
-	spin_lock_irqsave(&nvt->lock, flags);
-
-	/* set function enable flags */
-	nvt_cir_reg_write(nvt, CIR_IRCON_TXEN | CIR_IRCON_RXEN |
-			  CIR_IRCON_RXINV | CIR_IRCON_SAMPLE_PERIOD_SEL,
-			  CIR_IRCON);
-
-	/* clear all pending interrupts */
-	nvt_cir_reg_write(nvt, 0xff, CIR_IRSTS);
-
-	/* enable interrupts */
-	nvt_set_cir_iren(nvt);
-
-	spin_unlock_irqrestore(&nvt->lock, flags);
+	nvt_enable_cir(nvt);
 
 	return 0;
 }
@@ -1093,19 +1084,13 @@ static void nvt_remove(struct pnp_dev *pdev)
 static int nvt_suspend(struct pnp_dev *pdev, pm_message_t state)
 {
 	struct nvt_dev *nvt = pnp_get_drvdata(pdev);
-	unsigned long flags;
 
 	nvt_dbg("%s called", __func__);
 
-	spin_lock_irqsave(&nvt->lock, flags);
-
-	/* disable all CIR interrupts */
-	nvt_cir_reg_write(nvt, 0, CIR_IREN);
-
-	spin_unlock_irqrestore(&nvt->lock, flags);
-
-	/* disable cir logical dev */
-	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
+	mutex_lock(&nvt->rdev->lock);
+	if (nvt->rdev->users)
+		nvt_disable_cir(nvt);
+	mutex_unlock(&nvt->rdev->lock);
 
 	/* make sure wake is enabled */
 	nvt_enable_wake(nvt);
@@ -1122,6 +1107,11 @@ static int nvt_resume(struct pnp_dev *pdev)
 	nvt_cir_regs_init(nvt);
 	nvt_cir_wake_regs_init(nvt);
 
+	mutex_lock(&nvt->rdev->lock);
+	if (nvt->rdev->users)
+		nvt_enable_cir(nvt);
+	mutex_unlock(&nvt->rdev->lock);
+
 	return 0;
 }
 
-- 
2.17.0

[PATCH 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Michał Winiarski]

Doing writes when the device is disabled seems to be a NOOP.
Let's enable the device, write the values, and then disable it on init.
This changes the behavior for wake device, which is now being disabled
after init.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Sean Young <sean@mess.org>
---
 drivers/media/rc/nuvoton-cir.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
index eebd6fef5602..61b68cde35f1 100644
--- a/drivers/media/rc/nuvoton-cir.c
+++ b/drivers/media/rc/nuvoton-cir.c
@@ -535,6 +535,8 @@ static void nvt_set_cir_iren(struct nvt_dev *nvt)
 
 static void nvt_cir_regs_init(struct nvt_dev *nvt)
 {
+	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
+
 	/* set sample limit count (PE interrupt raised when reached) */
 	nvt_cir_reg_write(nvt, CIR_RX_LIMIT_COUNT >> 8, CIR_SLCH);
 	nvt_cir_reg_write(nvt, CIR_RX_LIMIT_COUNT & 0xff, CIR_SLCL);
@@ -546,10 +548,14 @@ static void nvt_cir_regs_init(struct nvt_dev *nvt)
 	/* clear hardware rx and tx fifos */
 	nvt_clear_cir_fifo(nvt);
 	nvt_clear_tx_fifo(nvt);
+
+	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
 }
 
 static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
 {
+	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
+
 	/*
 	 * Disable RX, set specific carrier on = low, off = high,
 	 * and sample period (currently 50us)
@@ -562,8 +568,7 @@ static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
 	/* clear any and all stray interrupts */
 	nvt_cir_wake_reg_write(nvt, 0xff, CIR_WAKE_IRSTS);
 
-	/* enable the CIR WAKE logical device */
-	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
+	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
 }
 
 static void nvt_enable_wake(struct nvt_dev *nvt)
-- 
2.17.0

Re: [PATCH 1/3] media: rc: nuvoton: Tweak the interrupt enabling dance

[Sean Young]

On Mon, May 21, 2018 at 04:38:01PM +0200, Michał Winiarski wrote:
> It appears that we need to enable CIR device before attempting to touch
> some of the registers. Previously, this was not a big issue, since we
> were rarely seeing nvt_close() getting called.
> 
> Unfortunately, since:
> cb84343fced1 ("media: lirc: do not call close() or open() on unregistered devices")
> 
> The initial open() during probe from rc_setup_rx_device() is no longer
> successful, which means that userspace clients will actually end up
> calling nvt_open()/nvt_close().
> And since nvt_open() is broken, the device doesn't seem to work as
> expected.

Since that commit was in v4.16, should we have the following:

Cc: stable@vger.kernel.org # v4.16+

On this commit (and not the other two, if I understand them correctly)?

Thanks,
Sean

> 
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199597
> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> Cc: Jarod Wilson <jarod@redhat.com>
> Cc: Sean Young <sean@mess.org>
> ---
>  drivers/media/rc/nuvoton-cir.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
> index 5e1d866a61a5..ce8949b6549d 100644
> --- a/drivers/media/rc/nuvoton-cir.c
> +++ b/drivers/media/rc/nuvoton-cir.c
> @@ -922,6 +922,9 @@ static int nvt_open(struct rc_dev *dev)
>  	struct nvt_dev *nvt = dev->priv;
>  	unsigned long flags;
>  
> +	/* enable the CIR logical device */
> +	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
> +
>  	spin_lock_irqsave(&nvt->lock, flags);
>  
>  	/* set function enable flags */
> @@ -937,9 +940,6 @@ static int nvt_open(struct rc_dev *dev)
>  
>  	spin_unlock_irqrestore(&nvt->lock, flags);
>  
> -	/* enable the CIR logical device */
> -	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
> -
>  	return 0;
>  }
>  
> -- 
> 2.17.0

Re: [PATCH 1/3] media: rc: nuvoton: Tweak the interrupt enabling dance

[Michał Winiarski]

On Mon, May 21, 2018 at 04:54:07PM +0100, Sean Young wrote:
> On Mon, May 21, 2018 at 04:38:01PM +0200, Michał Winiarski wrote:
> > It appears that we need to enable CIR device before attempting to touch
> > some of the registers. Previously, this was not a big issue, since we
> > were rarely seeing nvt_close() getting called.
> > 
> > Unfortunately, since:
> > cb84343fced1 ("media: lirc: do not call close() or open() on unregistered devices")
> > 
> > The initial open() during probe from rc_setup_rx_device() is no longer
> > successful, which means that userspace clients will actually end up
> > calling nvt_open()/nvt_close().
> > And since nvt_open() is broken, the device doesn't seem to work as
> > expected.
> 
> Since that commit was in v4.16, should we have the following:
> 
> Cc: stable@vger.kernel.org # v4.16+
> 
> On this commit (and not the other two, if I understand them correctly)?

Correct. I even had it in the series attached to the bugzilla.
Dropped it because the bug reporters have not confirmed that it fixes their
problem yet. (works for me though...)

-Michał

> 
> Thanks,
> Sean
> 
> > 
> > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199597
> > Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> > Cc: Jarod Wilson <jarod@redhat.com>
> > Cc: Sean Young <sean@mess.org>
> > ---
> >  drivers/media/rc/nuvoton-cir.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)

Re: [PATCH 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Sean Young]

On Mon, May 21, 2018 at 04:38:03PM +0200, Michał Winiarski wrote:
> Doing writes when the device is disabled seems to be a NOOP.
> Let's enable the device, write the values, and then disable it on init.
> This changes the behavior for wake device, which is now being disabled
> after init.

I don't have the datasheet so I might be misunderstanding this. We want
the IR wakeup to work fine even after kernel crash/power loss, right?

> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> Cc: Jarod Wilson <jarod@redhat.com>
> Cc: Sean Young <sean@mess.org>
> ---
>  drivers/media/rc/nuvoton-cir.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
> index eebd6fef5602..61b68cde35f1 100644
> --- a/drivers/media/rc/nuvoton-cir.c
> +++ b/drivers/media/rc/nuvoton-cir.c
> @@ -535,6 +535,8 @@ static void nvt_set_cir_iren(struct nvt_dev *nvt)
>  
>  static void nvt_cir_regs_init(struct nvt_dev *nvt)
>  {
> +	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
> +
>  	/* set sample limit count (PE interrupt raised when reached) */
>  	nvt_cir_reg_write(nvt, CIR_RX_LIMIT_COUNT >> 8, CIR_SLCH);
>  	nvt_cir_reg_write(nvt, CIR_RX_LIMIT_COUNT & 0xff, CIR_SLCL);
> @@ -546,10 +548,14 @@ static void nvt_cir_regs_init(struct nvt_dev *nvt)
>  	/* clear hardware rx and tx fifos */
>  	nvt_clear_cir_fifo(nvt);
>  	nvt_clear_tx_fifo(nvt);
> +
> +	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
>  }
>  
>  static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
>  {
> +	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
> +
>  	/*
>  	 * Disable RX, set specific carrier on = low, off = high,
>  	 * and sample period (currently 50us)
> @@ -562,8 +568,7 @@ static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
>  	/* clear any and all stray interrupts */
>  	nvt_cir_wake_reg_write(nvt, 0xff, CIR_WAKE_IRSTS);
>  
> -	/* enable the CIR WAKE logical device */
> -	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
> +	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);

The way I read this is that the CIR, not CIR_WAKE, is being disabled,
which seems contrary to what the commit message says.


Sean

>  }
>  
>  static void nvt_enable_wake(struct nvt_dev *nvt)
> -- 
> 2.17.0

Re: [PATCH 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Michał Winiarski]

On Thu, May 24, 2018 at 12:31:40PM +0100, Sean Young wrote:
> On Mon, May 21, 2018 at 04:38:03PM +0200, Michał Winiarski wrote:
> > Doing writes when the device is disabled seems to be a NOOP.
> > Let's enable the device, write the values, and then disable it on init.
> > This changes the behavior for wake device, which is now being disabled
> > after init.
> 
> I don't have the datasheet so I might be misunderstanding this. We want
> the IR wakeup to work fine even after kernel crash/power loss, right?

[snip]

Right, that makes sense. I completely ignored this scenario.
 
> > -	/* enable the CIR WAKE logical device */
> > -	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
> > +	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
> 
> The way I read this is that the CIR, not CIR_WAKE, is being disabled,
> which seems contrary to what the commit message says.
> 

That's a typo. And by accident it makes the wake_device work correctly :)
I think that registers init logic was still broken though, operating under the
assumption that the device is enabled on module load...

I guess we should just remove disable(LOGICAL_DEV_CIR) from wake_regs_init.

Have you already included this in any non-rebasing tree?
Should I send a v2 or fixup on top?

-Michał

> 
> Sean
> 
> >  }
> >  
> >  static void nvt_enable_wake(struct nvt_dev *nvt)
> > -- 
> > 2.17.0

Re: [PATCH 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Sean Young]

On Fri, May 25, 2018 at 03:35:23PM +0200, Michał Winiarski wrote:
> On Thu, May 24, 2018 at 12:31:40PM +0100, Sean Young wrote:
> > On Mon, May 21, 2018 at 04:38:03PM +0200, Michał Winiarski wrote:
> > > Doing writes when the device is disabled seems to be a NOOP.
> > > Let's enable the device, write the values, and then disable it on init.
> > > This changes the behavior for wake device, which is now being disabled
> > > after init.
> > 
> > I don't have the datasheet so I might be misunderstanding this. We want
> > the IR wakeup to work fine even after kernel crash/power loss, right?
> 
> [snip]
> 
> Right, that makes sense. I completely ignored this scenario.
>  
> > > -	/* enable the CIR WAKE logical device */
> > > -	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
> > > +	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
> > 
> > The way I read this is that the CIR, not CIR_WAKE, is being disabled,
> > which seems contrary to what the commit message says.
> > 
> 
> That's a typo. And by accident it makes the wake_device work correctly :)
> I think that registers init logic was still broken though, operating under the
> assumption that the device is enabled on module load...
> 
> I guess we should just remove disable(LOGICAL_DEV_CIR) from wake_regs_init.
> 
> Have you already included this in any non-rebasing tree?

Nothing has been applied yet.

> Should I send a v2 or fixup on top?

I don't have the hardware to test this, a v2 would be appreciated.

We're late in the release cycle and I'm wondering if this patch would also
solve the nuvoton probe problem:

https://patchwork.linuxtv.org/patch/49874/

Thanks,

Sean

[PATCH v2 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Michał Winiarski]

Doing writes when the device is disabled seems to be a NOOP.
For CIR device, we should enable it, intialize it, and then disable it
until it's opened. CIR_WAKE should always be enabled.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Sean Young <sean@mess.org>
---
Changes since v1:
 - Don't mix CIR_WAKE with CIR device
 - Correct the commit message
---
 drivers/media/rc/nuvoton-cir.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
index eebd6fef5602..b8299c9a9744 100644
--- a/drivers/media/rc/nuvoton-cir.c
+++ b/drivers/media/rc/nuvoton-cir.c
@@ -535,6 +535,8 @@ static void nvt_set_cir_iren(struct nvt_dev *nvt)
 
 static void nvt_cir_regs_init(struct nvt_dev *nvt)
 {
+	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR);
+
 	/* set sample limit count (PE interrupt raised when reached) */
 	nvt_cir_reg_write(nvt, CIR_RX_LIMIT_COUNT >> 8, CIR_SLCH);
 	nvt_cir_reg_write(nvt, CIR_RX_LIMIT_COUNT & 0xff, CIR_SLCL);
@@ -546,10 +548,14 @@ static void nvt_cir_regs_init(struct nvt_dev *nvt)
 	/* clear hardware rx and tx fifos */
 	nvt_clear_cir_fifo(nvt);
 	nvt_clear_tx_fifo(nvt);
+
+	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
 }
 
 static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
 {
+	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
+
 	/*
 	 * Disable RX, set specific carrier on = low, off = high,
 	 * and sample period (currently 50us)
@@ -561,9 +567,6 @@ static void nvt_cir_wake_regs_init(struct nvt_dev *nvt)
 
 	/* clear any and all stray interrupts */
 	nvt_cir_wake_reg_write(nvt, 0xff, CIR_WAKE_IRSTS);
-
-	/* enable the CIR WAKE logical device */
-	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
 }
 
 static void nvt_enable_wake(struct nvt_dev *nvt)
-- 
2.17.0

Re: [PATCH 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Michał Winiarski]

On Fri, May 25, 2018 at 02:59:41PM +0100, Sean Young wrote:
> On Fri, May 25, 2018 at 03:35:23PM +0200, Michał Winiarski wrote:
> > On Thu, May 24, 2018 at 12:31:40PM +0100, Sean Young wrote:
> > > On Mon, May 21, 2018 at 04:38:03PM +0200, Michał Winiarski wrote:
> > > > Doing writes when the device is disabled seems to be a NOOP.
> > > > Let's enable the device, write the values, and then disable it on init.
> > > > This changes the behavior for wake device, which is now being disabled
> > > > after init.
> > > 
> > > I don't have the datasheet so I might be misunderstanding this. We want
> > > the IR wakeup to work fine even after kernel crash/power loss, right?
> > 
> > [snip]
> > 
> > Right, that makes sense. I completely ignored this scenario.
> >  
> > > > -	/* enable the CIR WAKE logical device */
> > > > -	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
> > > > +	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
> > > 
> > > The way I read this is that the CIR, not CIR_WAKE, is being disabled,
> > > which seems contrary to what the commit message says.
> > > 
> > 
> > That's a typo. And by accident it makes the wake_device work correctly :)
> > I think that registers init logic was still broken though, operating under the
> > assumption that the device is enabled on module load...
> > 
> > I guess we should just remove disable(LOGICAL_DEV_CIR) from wake_regs_init.
> > 
> > Have you already included this in any non-rebasing tree?
> 
> Nothing has been applied yet.
> 
> > Should I send a v2 or fixup on top?
> 
> I don't have the hardware to test this, a v2 would be appreciated.
> 
> We're late in the release cycle and I'm wondering if this patch would also
> solve the nuvoton probe problem:
> 
> https://patchwork.linuxtv.org/patch/49874/

It causes us to go back to previous behavior (we're refcounting open/close,
with your patch initial open on my system is coming from kbd_connect(), so
userspace close() doesn't propagate to nuvoton-cir).

It passes my test of "load the module with debug=1, see if I'm getting
interrupts".

If there's any scenario in which->close() would be called, it's still going to
be broken.

-Michał

> 
> Thanks,
> 
> Sean

Re: [PATCH 3/3] media: rc: nuvoton: Keep device enabled during reg init

[Sean Young]

On Fri, May 25, 2018 at 04:42:02PM +0200, Michał Winiarski wrote:
> On Fri, May 25, 2018 at 02:59:41PM +0100, Sean Young wrote:
> > On Fri, May 25, 2018 at 03:35:23PM +0200, Michał Winiarski wrote:
> > > On Thu, May 24, 2018 at 12:31:40PM +0100, Sean Young wrote:
> > > > On Mon, May 21, 2018 at 04:38:03PM +0200, Michał Winiarski wrote:
> > > > > Doing writes when the device is disabled seems to be a NOOP.
> > > > > Let's enable the device, write the values, and then disable it on init.
> > > > > This changes the behavior for wake device, which is now being disabled
> > > > > after init.
> > > > 
> > > > I don't have the datasheet so I might be misunderstanding this. We want
> > > > the IR wakeup to work fine even after kernel crash/power loss, right?
> > > 
> > > [snip]
> > > 
> > > Right, that makes sense. I completely ignored this scenario.
> > >  
> > > > > -	/* enable the CIR WAKE logical device */
> > > > > -	nvt_enable_logical_dev(nvt, LOGICAL_DEV_CIR_WAKE);
> > > > > +	nvt_disable_logical_dev(nvt, LOGICAL_DEV_CIR);
> > > > 
> > > > The way I read this is that the CIR, not CIR_WAKE, is being disabled,
> > > > which seems contrary to what the commit message says.
> > > > 
> > > 
> > > That's a typo. And by accident it makes the wake_device work correctly :)
> > > I think that registers init logic was still broken though, operating under the
> > > assumption that the device is enabled on module load...
> > > 
> > > I guess we should just remove disable(LOGICAL_DEV_CIR) from wake_regs_init.
> > > 
> > > Have you already included this in any non-rebasing tree?
> > 
> > Nothing has been applied yet.
> > 
> > > Should I send a v2 or fixup on top?
> > 
> > I don't have the hardware to test this, a v2 would be appreciated.
> > 
> > We're late in the release cycle and I'm wondering if this patch would also
> > solve the nuvoton probe problem:
> > 
> > https://patchwork.linuxtv.org/patch/49874/
> 
> It causes us to go back to previous behavior (we're refcounting open/close,
> with your patch initial open on my system is coming from kbd_connect(), so
> userspace close() doesn't propagate to nuvoton-cir).
> 
> It passes my test of "load the module with debug=1, see if I'm getting
> interrupts".
> 
> If there's any scenario in which->close() would be called, it's still going to
> be broken.

Great, thank you very much for testing that. I've created a pull request
for the v2 version.


Sean