Re: [PATCH] drivers/perf: fix return value check in ali_drw_pmu_probe()

[Will Deacon]

On Sat, Sep 24, 2022 at 11:21:27AM +0800, Sun Ke wrote:
> In case of error, devm_ioremap_resource() returns ERR_PTR(),
> and never returns NULL. The NULL test in the return value
> check should be replaced with IS_ERR().
> 
> Fixes: cf7b61073e45 ("drivers/perf: add DDR Sub-System Driveway PMU driver for Yitian 710 SoC")
> Signed-off-by: Sun Ke <sunke32@xxxxxxxxxx>
> ---
>  drivers/perf/alibaba_uncore_drw_pmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
> index 82729b874f09..a7689fecb49d 100644
> --- a/drivers/perf/alibaba_uncore_drw_pmu.c
> +++ b/drivers/perf/alibaba_uncore_drw_pmu.c
> @@ -658,8 +658,8 @@ static int ali_drw_pmu_probe(struct platform_device *pdev)
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	drw_pmu->cfg_base = devm_ioremap_resource(&pdev->dev, res);
> -	if (!drw_pmu->cfg_base)
> -		return -ENOMEM;
> +	if (IS_ERR(drw_pmu->cfg_base))
> +		return PTR_ERR(drw_pmu->cfg_base);
>  
>  	name = devm_kasprintf(drw_pmu->dev, GFP_KERNEL, "ali_drw_%llx",
>  			      (u64) (res->start >> ALI_DRW_PMU_PA_SHIFT));

Acked-by: Will Deacon <will@xxxxxxxxxx>

Catalin can pick this one up as a fix.

Cheers,

Will