[1/3] media: rc: drivers should produce alternate pulse and space timing events

[jbrunet@baylibre.com (Jerome Brunet)]

On Tue, 2018-06-19 at 13:57 +0100, Sean Young wrote:
> On Tue, Jun 19, 2018 at 02:08:12PM +0200, Jerome Brunet wrote:
> > On Sat, 2018-05-12 at 11:55 +0100, Sean Young wrote:
> > > Report an error if this is not the case or any problem with the generated
> > > raw events.
> > 
> > Hi,
> > 
> > Since the inclusion of this patch, every 3 to 15 seconds, I get the following
> > message: 
> > 
> >  "rc rc0: two consecutive events of type space"
> > 
> > on the console of amlogic s400 platform (arch/arm64/boot/dts/amlogic/meson-axg-
> > s400.dts). I don't know much about ir protocol and surely there is something
> > worth investigating in the related driver, but ...
> > 
> > > 
> > > Signed-off-by: Sean Young <sean@mess.org>
> > > ---
> > >  drivers/media/rc/rc-ir-raw.c | 19 +++++++++++++++----
> > >  1 file changed, 15 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
> > > index 2e50104ae138..49c56da9bc67 100644
> > > --- a/drivers/media/rc/rc-ir-raw.c
> > > +++ b/drivers/media/rc/rc-ir-raw.c
> > > @@ -22,16 +22,27 @@ static int ir_raw_event_thread(void *data)
> > >  {
> > >  	struct ir_raw_event ev;
> > >  	struct ir_raw_handler *handler;
> > > -	struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
> > > +	struct ir_raw_event_ctrl *raw = data;
> > > +	struct rc_dev *dev = raw->dev;
> > >  
> > >  	while (1) {
> > >  		mutex_lock(&ir_raw_handler_lock);
> > >  		while (kfifo_out(&raw->kfifo, &ev, 1)) {
> > > +			if (is_timing_event(ev)) {
> > > +				if (ev.duration == 0)
> > > +					dev_err(&dev->dev, "nonsensical timing event of duration 0");
> > > +				if (is_timing_event(raw->prev_ev) &&
> > > +				    !is_transition(&ev, &raw->prev_ev))
> > > +					dev_err(&dev->dev, "two consecutive events of type %s",
> > > +						TO_STR(ev.pulse));
> > > +				if (raw->prev_ev.reset && ev.pulse == 0)
> > > +					dev_err(&dev->dev, "timing event after reset should be pulse");
> > > +			}
> > 
> > ... considering that we continue the processing as if nothing happened, is it
> > really an error ? 
> > 
> > Could we consider something less invasive ? like dev_dbg() or dev_warn_once() ?
> 
> Maybe it should be dev_warn(). The fact that it is not dev_warn_once() means
> that we now know this occurs regularly.

It seems weird to report this over and over again.

> 
> Would you mind testing the following patch please?
> 
> Thanks
> 
> Sean
> 
> From 6a44fbe4738d230b9cf378777e7e9a93e5fda726 Mon Sep 17 00:00:00 2001
> From: Sean Young <sean@mess.org>
> Date: Tue, 19 Jun 2018 13:50:36 +0100
> Subject: [PATCH] media: rc: meson: rc rc0: two consecutive events of type
>  space
> 
> The meson generates one edge per interrupt. The duration is encoded in 12
> bits of 10 microseconds, so it can only encoding a maximum of 40
> milliseconds. As a result, it can produce multiple space events.
> 
> Signed-off-by: Sean Young <sean@mess.org>
> ---
>  drivers/media/rc/meson-ir.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/rc/meson-ir.c b/drivers/media/rc/meson-ir.c
> index f449b35d25e7..9747426719b2 100644
> --- a/drivers/media/rc/meson-ir.c
> +++ b/drivers/media/rc/meson-ir.c
> @@ -97,7 +97,8 @@ static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
>  	status = readl_relaxed(ir->reg + IR_DEC_STATUS);
>  	rawir.pulse = !!(status & STATUS_IR_DEC_IN);
>  
> -	ir_raw_event_store_with_timeout(ir->rc, &rawir);
> +	if (ir_raw_event_store_with_filter(ir->rc, &rawir))
> +		ir_raw_event_handle(ir->rc);
>  
>  	spin_unlock(&ir->lock);
>  

Solve the problem on meson. Thx
Feel free to add this submitting the patch

Tested-by: Jerome Brunet <jbrunet@baylibre.com>

Cheers