Re: [PATCH next] perf: arm-ni: Fix an NULL vs IS_ERR() bug

[Robin Murphy]

On 2024-09-11 8:39 am, Dan Carpenter wrote:
> The devm_ioremap() function never returns error pointers, it returns a
> NULL pointer if there is an error.

Ah, this code went through a few evolutions, and apparently I missed 
that devm_ioremap() and devm_ioremap_resource() helpfully have different 
behaviour, urgh. Thanks Dan!

Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>

> Fixes: 4d5a7680f2b4 ("perf: Add driver for Arm NI-700 interconnect PMU")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
>   drivers/perf/arm-ni.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/perf/arm-ni.c b/drivers/perf/arm-ni.c
> index b72df3aea93e..90fcfe693439 100644
> --- a/drivers/perf/arm-ni.c
> +++ b/drivers/perf/arm-ni.c
> @@ -603,8 +603,8 @@ static int arm_ni_probe(struct platform_device *pdev)
>   	 */
>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>   	base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> -	if (IS_ERR(base))
> -		return PTR_ERR(base);
> +	if (!base)
> +		return -ENOMEM;
>   
>   	arm_ni_probe_domain(base, &cfg);
>   	if (cfg.type != NI_GLOBAL)