Re: drivers/iio/accel/kionix-kx022a.c:1053 kx022a_probe_internal() warn: passing zero to 'dev_err_probe'

[Matti Vaittinen <mazziesaccount@gmail.com>]

On 5/12/23 08:41, Dan Carpenter wrote:
> On Fri, May 12, 2023 at 08:16:02AM +0300, Matti Vaittinen wrote:
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1046  	irq = fwnode_irq_get_byname(fwnode, "INT1");
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1047  	if (irq > 0) {
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1048  		data->inc_reg = KX022A_REG_INC1;
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1049  		data->ien_reg = KX022A_REG_INC4;
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1050  	} else {
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1051  		irq = fwnode_irq_get_byname(fwnode, "INT2");
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24  1052  		if (irq <= 0)
>>>                                                                       ^^^^^^^^
>>> This code assumes fwnode_irq_get_byname() can return zero.
>>>
>>> 7c1d1677b3227c Matti Vaittinen 2022-10-24 @1053  			return dev_err_probe(dev, irq, "No suitable IRQ\n");
>>>
>>> But fortunately, it can't otherwise this would return success.
>>>
>>
>> Ouch. Actually, the fwnode_irq_get_byname() can return zero on device-tree
>> mapping error. I did actually send a patch to address this some time ago:
>> https://lore.kernel.org/lkml/cover.1666710197.git.mazziesaccount@gmail.com/
>>
> 
> Ah.  I just went by the documentation instead of looking at the code.
> 
> Originally a bunch of irq functions return NO_IRQ on error which was a
> design mistake...  irq_of_parse_and_map() still returns zero on error
> instead of negative error codes.  I wrote a check for that yesterday.
> 
> drivers/gpu/drm/msm/dsi/dsi_host.c:1949 msm_dsi_host_init() warn: irq_of_parse_and_map() returns zero on failure
> drivers/dma/ti/edma.c:2405 edma_probe() warn: irq_of_parse_and_map() returns zero on failure
> drivers/dma/ti/edma.c:2421 edma_probe() warn: irq_of_parse_and_map() returns zero on failure
> drivers/net/ethernet/xilinx/ll_temac_main.c:1570 temac_probe() warn: irq_of_parse_and_map() returns zero on failure
> drivers/net/ethernet/xilinx/ll_temac_main.c:1573 temac_probe() warn: irq_of_parse_and_map() returns zero on failure
> drivers/ata/sata_mv.c:4094 mv_platform_probe() warn: irq_of_parse_and_map() returns zero on failure
> 
> It would be good if we could apply your patch, otherwise I could create
> an explicit check for fwnode_irq_get_byname() returns.

I guess I can re-spin the series. Let's see if there is some good 
suggestion(s) on how to fix the i2c-smbus.

> Ideally, everything would just return negative error codes on error.

I definitely agree.


Yours,
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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