Subject: Re: [PATCH -next V4 2/2] sata_fsl: fix warning in remove_proc_entry
 when rmmod sata_fsl
To:     Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        <linux-ide@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC:     <sergei.shtylyov@gmail.com>, <yebin10@huawei.com>,
        <yukuai3@huawei.com>, Hulk Robot <hulkci@huawei.com>
References: <20211123014159.3442998-1-libaokun1@huawei.com>
 <20211123014159.3442998-3-libaokun1@huawei.com>
 <c760f12c-c296-9184-7952-9b76c84fe48f@opensource.wdc.com>
From:   "libaokun (A)" <libaokun1@huawei.com>
Message-ID: <e4e32cd3-4bfe-9207-0bc2-b6367204c386@huawei.com>
Date:   Fri, 26 Nov 2021 09:36:42 +0800
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在 2021/11/26 7:47, Damien Le Moal 写道:
> 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.

I've seen a similar change in cf9441adb1a3("ASoC: Remove dev_err() usage 
after platform_get_irq()"),

but I'm not sure if it needs to be changed here. Now that you have 
pointed out the problem,

I will send a patch V5 with the changes suggested by you. Thank you!


>
>>   		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;
>>   }
>>   
>>
>
-- 
With Best Regards,
Baokun Li
.