Re: [PATCH -next V4 2/2] sata_fsl: fix warning in remove_proc_entry when rmmod sata_fsl

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 2021/11/23 10:41, Baokun Li wrote:
> Trying to remove the fsl-sata module in the PPC64 GNU/Linux
> leads to the following warning:
>  ------------[ cut here ]------------
>  remove_proc_entry: removing non-empty directory 'irq/69',
>    leaking at least 'fsl-sata[ff0221000.sata]'
>  WARNING: CPU: 3 PID: 1048 at fs/proc/generic.c:722
>    .remove_proc_entry+0x20c/0x220
>  IRQMASK: 0
>  NIP [c00000000033826c] .remove_proc_entry+0x20c/0x220
>  LR [c000000000338268] .remove_proc_entry+0x208/0x220
>  Call Trace:
>   .remove_proc_entry+0x208/0x220 (unreliable)
>   .unregister_irq_proc+0x104/0x140
>   .free_desc+0x44/0xb0
>   .irq_free_descs+0x9c/0xf0
>   .irq_dispose_mapping+0x64/0xa0
>   .sata_fsl_remove+0x58/0xa0 [sata_fsl]
>   .platform_drv_remove+0x40/0x90
>   .device_release_driver_internal+0x160/0x2c0
>   .driver_detach+0x64/0xd0
>   .bus_remove_driver+0x70/0xf0
>   .driver_unregister+0x38/0x80
>   .platform_driver_unregister+0x14/0x30
>   .fsl_sata_driver_exit+0x18/0xa20 [sata_fsl]
>  ---[ end trace 0ea876d4076908f5 ]---
> 
> The driver creates the mapping by calling irq_of_parse_and_map(),
> so it also has to dispose the mapping. But the easy way out is to
> simply use platform_get_irq() instead of irq_of_parse_map(). Also
> we should adapt return value checking and propagate error values.
> 
> In this case the mapping is not managed by the device but by
> the of core, so the device has not to dispose the mapping.
> 
> Fixes: faf0b2e5afe7 ("drivers/ata: add support to Freescale 3.0Gbps SATA Controller")
> Cc: stable@vger.kernel.org
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Baokun Li <libaokun1@huawei.com>
> ---
> V1->V2:
> 	Adapt return value checking and propagate error values.
> V2->V3:
> 	Add fixed and CC stable.
> 
>  drivers/ata/sata_fsl.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
> index 2eb216792695..8e7c49793f91 100644
> --- a/drivers/ata/sata_fsl.c
> +++ b/drivers/ata/sata_fsl.c
> @@ -1490,8 +1490,9 @@ static int sata_fsl_probe(struct platform_device *ofdev)
>  	host_priv->ssr_base = ssr_base;
>  	host_priv->csr_base = csr_base;
>  
> -	irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
> -	if (!irq) {
> +	irq = platform_get_irq(ofdev, 0);
> +	if (irq < 0) {
> +		retval = irq;
>  		dev_err(&ofdev->dev, "invalid irq from platform\n");

Nit: platform_get_irq() already prints an error message in case of failure. So
while at it, you could remove this one here.

>  		goto error_exit_with_cleanup;
>  	}
> @@ -1567,8 +1568,6 @@ static int sata_fsl_remove(struct platform_device *ofdev)
>  
>  	ata_host_detach(host);
>  
> -	irq_dispose_mapping(host_priv->irq);
> -
>  	return 0;
>  }
>  
> 


-- 
Damien Le Moal
Western Digital Research