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authorOliver Hartkopp <oliver@hartkopp.net>2009-12-12 07:13:21 +0300
committerDavid S. Miller <davem@davemloft.net>2009-12-14 06:47:42 +0300
commitc7cd606f60e7679c7f9eee7010f02a6f000209c1 (patch)
tree31c19fd7617ede807757b0ae5c29d218587dc43f /drivers/net/can/at91_can.c
parentd90a909e1f3e006a1d57fe11fd417173b6494701 (diff)
downloadlinux-c7cd606f60e7679c7f9eee7010f02a6f000209c1.tar.xz
can: Fix data length code handling in rx path
A valid CAN dataframe can have a data length code (DLC) of 0 .. 8 data bytes. When reading the CAN controllers register the 4-bit value may contain values from 0 .. 15 which may exceed the reserved space in the socket buffer! The ISO 11898-1 Chapter 8.4.2.3 (DLC field) says that register values > 8 should be reduced to 8 without any error reporting or frame drop. This patch introduces a new helper macro to cast a given 4-bit data length code (dlc) to __u8 and ensure the DLC value to be max. 8 bytes. The different handlings in the rx path of the CAN netdevice drivers are fixed. Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/can/at91_can.c')
-rw-r--r--drivers/net/can/at91_can.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index cbe3fce53e3b..d0ec17878ffc 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -474,7 +474,7 @@ static void at91_read_mb(struct net_device *dev, unsigned int mb,
reg_msr = at91_read(priv, AT91_MSR(mb));
if (reg_msr & AT91_MSR_MRTR)
cf->can_id |= CAN_RTR_FLAG;
- cf->can_dlc = min_t(__u8, (reg_msr >> 16) & 0xf, 8);
+ cf->can_dlc = get_can_dlc((reg_msr >> 16) & 0xf);
*(u32 *)(cf->data + 0) = at91_read(priv, AT91_MDL(mb));
*(u32 *)(cf->data + 4) = at91_read(priv, AT91_MDH(mb));