Re: [PATCH v3 01/33] staging: rtl8192e: Declare ethernet addresses as __aligned(2)

[Mateusz Kulikowski]

On 10.05.2015 00:29, Joe Perches wrote:
> On Sat, 2015-05-09 at 23:18 +0200, Mateusz Kulikowski wrote:
>> Add __aligned(2) into ethernet addresses allocated on stack or in non-packed
>> structures. Use ETH_ALEN as array length in places where it was hardcoded to 6.
> []
>> diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c
> []
>> @@ -321,7 +321,8 @@ static void rtl8192_read_eeprom_info(struct net_device *dev)
>>  	u8 ICVer8192, ICVer8256;
>>  	u16 i, usValue, IC_Version;
>>  	u16 EEPROMId;
>> -	u8 bMac_Tmp_Addr[6] = {0x00, 0xe0, 0x4c, 0x00, 0x00, 0x01};
>> +	u8 bMac_Tmp_Addr[ETH_ALEN] __aligned(2) = {0x00, 0xe0, 0x4c,
>> +						   0x00, 0x00, 0x01};
> 
> While this is safe, as this follows a u16, it's unnecessary.
> 
> Also, ideally, this would be
> 	u8 foo[ETH_ALEN] = {
> 		1, 2, 3, 4, 5, 6
> 	};
> or just left on a single line.

I put __aligned to most places to show authors intention and to prevent someone from breaking it by 
(for example) removing u16 above due some refactoring.

If you insist - I will remove it.

> 
>> diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
> []
>> @@ -2573,8 +2573,9 @@ static int rtl8192_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
>>  	int ret = -1;
>>  	struct rtllib_device *ieee = priv->rtllib;
>>  	u32 key[4];
>> -	u8 broadcast_addr[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
>> -	u8 zero_addr[6] = {0};
>> +	u8 broadcast_addr[ETH_ALEN] __aligned(2) = {0xff, 0xff, 0xff,
>> +						    0xff, 0xff, 0xff};
>> +	u8 zero_addr[ETH_ALEN] __aligned(2) = {0};
> 
> If these are used only in tests, these are probably better
> being removed and using is_<foo>_ether_addr or maybe
> if these used in things other than tests, being converted
> to static const so they are not reinitialized on each
> call of the function.
> 

zero_addr in fact is used only for comparison - I'll use is_eth_zero_addr;

broadcast is used as parameter so will make it static const (and update used functions to accept const ethaddr)

Regards,
Mateusz
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