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

From: Sergei Shtylyov <sergei.shtylyov@gmail.com>
To: Baokun Li <libaokun1@huawei.com>,
	damien.lemoal@opensource.wdc.com, axboe@kernel.dk, tj@kernel.org,
	linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: yebin10@huawei.com, yukuai3@huawei.com, Hulk Robot <hulkci@huawei.com>
Subject: Re: [PATCH -next 2/2] sata_fsl: fix warning in remove_proc_entry when rmmod sata_fsl
Date: Fri, 19 Nov 2021 18:43:28 +0300	[thread overview]
Message-ID: <283712c0-bab7-de13-fc27-6ae2e6f9532f@gmail.com> (raw)
In-Reply-To: <20211119041128.2436889-3-libaokun1@huawei.com>

Hello!

On 19.11.2021 7:11, 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().

    Not that easy. :-)

> 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.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Baokun Li <libaokun1@huawei.com>
> ---
>   drivers/ata/sata_fsl.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
> index 30759fd1c3a2..011daac4a14e 100644
> --- a/drivers/ata/sata_fsl.c
> +++ b/drivers/ata/sata_fsl.c
> @@ -1493,7 +1493,7 @@ 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);
> +	irq = platform_get_irq(ofdev, 0);
>   	if (!irq) {

	if (irq < 0) {

    platform_get_irq() returns negative error codes, not 0 on failure.

[...]

MBR, Sergey