Re: [PATCH v2 01/15] genirq/devres: Add error information printing for devm_request_threaded_irq()

[Ahmad Fatoum]

On 27.06.23 12:12, Yangtao Li wrote:
> Ensure that all error handling branches print error information. In this
> way, when this function fails, the upper-layer functions can directly
> return an error code without missing debugging information. Otherwise,
> the error message will be printed redundantly or missing.
> 
> There are more than 700 calls to the devm_request_threaded_irq method.
> Most drivers only request one interrupt resource, and these error
> messages are basically the same. If error messages are printed
> everywhere, more than 1000 lines of code can be saved by removing the
> msg in the driver.
> 
> Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
> ---
>  kernel/irq/devres.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
> index f6e5515ee077..fcb946ffb7ec 100644
> --- a/kernel/irq/devres.c
> +++ b/kernel/irq/devres.c
> @@ -58,8 +58,10 @@ int devm_request_threaded_irq(struct device *dev, unsigned int irq,
>  
>  	dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
>  			  GFP_KERNEL);
> -	if (!dr)
> +	if (!dr) {
> +		dev_err(dev, "Failed to allocate device resource data\n");

Why not use dev_err_probe too? Could turn this block into a oneliner.

>  		return -ENOMEM;
> +	}
>  
>  	if (!devname)
>  		devname = dev_name(dev);
> @@ -67,6 +69,7 @@ int devm_request_threaded_irq(struct device *dev, unsigned int irq,
>  	rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
>  				  dev_id);
>  	if (rc) {
> +		dev_err_probe(dev, rc, "Failed to request threaded irq%d: %d\n", irq, rc);

No need to format rc with %d. dev_err_probe will already do this for you.

>  		devres_free(dr);
>  		return rc;
>  	}

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