Subject: Re: [PATCH -next V5 2/2] sata_fsl: fix warning in remove_proc_entry
 when rmmod sata_fsl
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, stable@vger.kernel.org,
        Hulk Robot <hulkci@huawei.com>
References: <20211126020307.2168767-1-libaokun1@huawei.com>
 <20211126020307.2168767-3-libaokun1@huawei.com>
From:   Sergei Shtylyov <sergei.shtylyov@gmail.com>
Message-ID: <d54fd029-77e3-524a-65ab-90761338e1db@gmail.com>
Date:   Fri, 26 Nov 2021 22:44:22 +0300
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On 11/26/21 5:03 AM, 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>

Reviewed-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>

MBR, Sergei