On 3/14/2018 5:10 PM, Kalle Valo wrote:
Rafał Miłecki <rafal@xxxxxxxxxx> writes:
+ unsigned char *eth_data = skb_mac_header(skb) + ETH_HLEN;
+#if !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
#ifndef?
I followed what is used in the include/linux/etherdevice.h. Is that a
good exceuse? Could it be there any some good reason for #if defined()?
Don't know, maybe just a matter of taste? But it would be nice to know
the background behind #ifdef vs #if defined(), never figured it out why
two different forms.
Well. In this case you could use either one, but if you have more
conditions #if defined() is bit more efficient:
#ifdef A
#ifdef B
#endif
#endif
vs.
#if defined(A) && defined(B)
Regards,
Arend
