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Subject: Re: [PATCH] net: stmmac: Fix signedness bug in
 stmmac_probe_config_dt()
To:     Andreas Schwab <schwab@linux-m68k.org>
References: <20200818143952.50752-1-yuehaibing@huawei.com>
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From:   Yuehaibing <yuehaibing@huawei.com>
Message-ID: <e8c4e539-d230-2add-6840-ebe1097b8130@huawei.com>
Date:   Tue, 18 Aug 2020 23:15:43 +0800
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On 2020/8/18 22:51, Andreas Schwab wrote:
> On Aug 18 2020, YueHaibing wrote:
> 
>> The "plat->phy_interface" variable is an enum and in this context GCC
>> will treat it as an unsigned int so the error handling is never
>> triggered.
>>
>> Fixes: b9f0b2f634c0 ("net: stmmac: platform: fix probe for ACPI devices")
>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>> ---
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> index f32317fa75c8..b5b558b02e7d 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> @@ -413,7 +413,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>>  	}
>>  
>>  	plat->phy_interface = device_get_phy_mode(&pdev->dev);
>> -	if (plat->phy_interface < 0)
>> +	if ((int)plat->phy_interface < 0)
>>  		return ERR_PTR(plat->phy_interface);
> 
> I don't think the conversion to long when passed to ERR_PTR will produce
> a negative value either (if long is wider than unsigned int).

Thanks, will respin.
> 
> Andreas.
>