serial: imx: simplify some conditions related to dma
[linux/fpc-iii.git] / Documentation / ABI / testing / sysfs-platform-at91
blob4cc6a865ae662f6252057aff396d42d837a566b6
1 What:           /sys/devices/platform/at91_can/net/<iface>/mb0_id
2 Date:           January 2011
3 KernelVersion:  2.6.38
4 Contact:        Marc Kleine-Budde <kernel@pengutronix.de>
5 Description:
6                 Value representing the can_id of mailbox 0.
8                 Default: 0x7ff (standard frame)
10                 Due to a chip bug (errata 50.2.6.3 & 50.3.5.3 in
11                 "AT91SAM9263 Preliminary 6249H-ATARM-27-Jul-09") the
12                 contents of mailbox 0 may be send under certain
13                 conditions (even if disabled or in rx mode).
15                 The workaround in the errata suggests not to use the
16                 mailbox and load it with an unused identifier.
18                 In order to use an extended can_id add the
19                 CAN_EFF_FLAG (0x80000000U) to the can_id. Example:
21                 - standard id 0x7ff:
22                 echo 0x7ff      > /sys/class/net/can0/mb0_id
24                 - extended id 0x1fffffff:
25                 echo 0x9fffffff > /sys/class/net/can0/mb0_id