Messages in this thread | | | From | Lino Sanfilippo <> | Subject | Question concerning function illegal_highdma | Date | Tue, 8 Mar 2016 11:32:26 +0100 |
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Hi all,
while trying to understand the meaning of the net_device flag NETIF_F_HIGHDMA I came across the function illegal_highdma() which seems to perform two tasks:
1. Check if a network interface is able to handle high memory pages 2. Check if a network interface is able to handle the resulting DMA addresses
What I dont understand is why both conditions are only checked if CONFIG_HIGHMEM is set. For 1. this makes sense, of course. But why is 2. also only checked with CONFIG_HIGHMEM? Should not 2. always be checked, regardless of whether high memory exists in the system or not?
Thanks for any enlightenment in advance!
Regards, Lino
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