tree 5a55caed3d5df29c52fdede81840fd0c1999f590
parent 427db97df1ee721c20bdc9a66db8a9e1da719855
author Finn Thain <fthain@telegraphics.com.au> 1579730846 +1100
committer David S. Miller <davem@davemloft.net> 1579811077 +0100

net/sonic: Fix receive buffer handling

The SONIC can sometimes advance its rx buffer pointer (RRP register)
without advancing its rx descriptor pointer (CRDA register). As a result
the index of the current rx descriptor may not equal that of the current
rx buffer. The driver mistakenly assumes that they are always equal.
This assumption leads to incorrect packet lengths and possible packet
duplication. Avoid this by calling a new function to locate the buffer
corresponding to a given descriptor.

Fixes: efcce839360f ("[PATCH] macsonic/jazzsonic network drivers update")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>