Re: [PATCH v2 3/7] Input: iqs7222 - report malformed properties

[Jeff LaBundy <jeff@labundy.com>]

Hi Mattijs,

On Fri, Oct 07, 2022 at 03:12:17PM +0200, Mattijs Korpershoek wrote:
> On Thu, Sep 15, 2022 at 23:31, Jeff LaBundy <jeff@labundy.com> wrote:
> 
> > Nonzero return values of several calls to fwnode_property_read_u32()
> > are silently ignored, leaving no way to know the properties were not
> > applied in the event of an error.
> >
> > Solve this problem by evaluating fwnode_property_read_u32()'s return
> > value, and reporting an error for any nonzero return value not equal
> > to -EINVAL which indicates the property was absent altogether.
> >
> > Fixes: e505edaedcb9 ("Input: add support for Azoteq IQS7222A/B/C")
> > Signed-off-by: Jeff LaBundy <jeff@labundy.com>
> > ---
> > Changes in v2:
> >  - Used -EINVAL returned by fwnode_property_read_u32() to indicate an absent
> >    optional property as opposed to calling fwnode_property_present()
> >  - Updated commit message
> >
> >  drivers/input/misc/iqs7222.c | 43 +++++++++++++++++++++++++++++-------
> >  1 file changed, 35 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/input/misc/iqs7222.c b/drivers/input/misc/iqs7222.c
> > index d39b3fdfb849..36c3b24e99a3 100644
> > --- a/drivers/input/misc/iqs7222.c
> > +++ b/drivers/input/misc/iqs7222.c
> > @@ -1820,8 +1820,9 @@ static int iqs7222_parse_chan(struct iqs7222_private *iqs7222,
> >  		chan_setup[0] |= IQS7222_CHAN_SETUP_0_REF_MODE_FOLLOW;
> >  		chan_setup[4] = val * 42 + 1048;
> >  
> > -		if (!fwnode_property_read_u32(chan_node, "azoteq,ref-weight",
> > -					      &val)) {
> > +		error = fwnode_property_read_u32(chan_node, "azoteq,ref-weight",
> > +						 &val);
> > +		if (!error) {
> >  			if (val > U16_MAX) {
> >  				dev_err(&client->dev,
> >  					"Invalid %s reference weight: %u\n",
> > @@ -1830,6 +1831,11 @@ static int iqs7222_parse_chan(struct iqs7222_private *iqs7222,
> >  			}
> >  
> >  			chan_setup[5] = val;
> > +		} else if (error != -EINVAL) {
> > +			dev_err(&client->dev,
> > +				"Failed to read %s reference weight: %d\n",
> > +				fwnode_get_name(chan_node), error);
> > +			return error;
> >  		}
> >  
> >  		/*
> > @@ -1902,9 +1908,10 @@ static int iqs7222_parse_chan(struct iqs7222_private *iqs7222,
> >  		if (!event_node)
> >  			continue;
> >  
> > -		if (!fwnode_property_read_u32(event_node,
> > -					      "azoteq,timeout-press-ms",
> > -					      &val)) {
> > +		error = fwnode_property_read_u32(event_node,
> > +						 "azoteq,timeout-press-ms",
> > +						 &val);
> > +		if (!error) {
> >  			/*
> >  			 * The IQS7222B employs a global pair of press timeout
> >  			 * registers as opposed to channel-specific registers.
> > @@ -1924,6 +1931,11 @@ static int iqs7222_parse_chan(struct iqs7222_private *iqs7222,
> >  
> >  			*setup &= ~(U8_MAX << i * 8);
> >  			*setup |= (val / 500 << i * 8);
> > +		} else if (error != -EINVAL) {
> > +			dev_err(&client->dev,
> > +				"Failed to read %s press timeout: %d\n",
> > +				fwnode_get_name(event_node), error);
> 
> Shouldn't we call fwnode_handle_put(event_node); here?
> It's what we do in the error path just above (line 2029)

Thank you for your review and for finding this; it's a great catch. I
will send out a v3 after the merge window with this fixed.

> 
> With that added, feel free to include:
> 
> Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> 
> > +			return error;
> >  		}
> >  
> >  		error = iqs7222_parse_event(iqs7222, event_node, chan_index,
> > @@ -2028,7 +2040,8 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
> >  	if (fwnode_property_present(sldr_node, "azoteq,use-prox"))
> >  		sldr_setup[4 + reg_offset] -= 2;
> >  
> > -	if (!fwnode_property_read_u32(sldr_node, "azoteq,slider-size", &val)) {
> > +	error = fwnode_property_read_u32(sldr_node, "azoteq,slider-size", &val);
> > +	if (!error) {
> >  		if (!val || val > dev_desc->sldr_res) {
> >  			dev_err(&client->dev, "Invalid %s size: %u\n",
> >  				fwnode_get_name(sldr_node), val);
> > @@ -2042,9 +2055,14 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
> >  			sldr_setup[2] |= (val / 16 <<
> >  					  IQS7222_SLDR_SETUP_2_RES_SHIFT);
> >  		}
> > +	} else if (error != -EINVAL) {
> > +		dev_err(&client->dev, "Failed to read %s size: %d\n",
> > +			fwnode_get_name(sldr_node), error);
> > +		return error;
> >  	}
> >  
> > -	if (!fwnode_property_read_u32(sldr_node, "azoteq,top-speed", &val)) {
> > +	error = fwnode_property_read_u32(sldr_node, "azoteq,top-speed", &val);
> > +	if (!error) {
> >  		if (val > (reg_offset ? U16_MAX : U8_MAX * 4)) {
> >  			dev_err(&client->dev, "Invalid %s top speed: %u\n",
> >  				fwnode_get_name(sldr_node), val);
> > @@ -2057,9 +2075,14 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
> >  			sldr_setup[2] &= ~IQS7222_SLDR_SETUP_2_TOP_SPEED_MASK;
> >  			sldr_setup[2] |= (val / 4);
> >  		}
> > +	} else if (error != -EINVAL) {
> > +		dev_err(&client->dev, "Failed to read %s top speed: %d\n",
> > +			fwnode_get_name(sldr_node), error);
> > +		return error;
> >  	}
> >  
> > -	if (!fwnode_property_read_u32(sldr_node, "linux,axis", &val)) {
> > +	error = fwnode_property_read_u32(sldr_node, "linux,axis", &val);
> > +	if (!error) {
> >  		u16 sldr_max = sldr_setup[3] - 1;
> >  
> >  		if (!reg_offset) {
> > @@ -2073,6 +2096,10 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
> >  
> >  		input_set_abs_params(iqs7222->keypad, val, 0, sldr_max, 0, 0);
> >  		iqs7222->sl_axis[sldr_index] = val;
> > +	} else if (error != -EINVAL) {
> > +		dev_err(&client->dev, "Failed to read %s axis: %d\n",
> > +			fwnode_get_name(sldr_node), error);
> > +		return error;
> >  	}
> >  
> >  	if (dev_desc->wheel_enable) {
> > -- 
> > 2.34.1

Kind regards,
Jeff LaBundy