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| author | Vincent Mailhol <mailhol.vincent@wanadoo.fr> | 2022-07-19 17:35:48 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-17 16:14:53 +0300 |
| commit | f4303216f45266b949bfe7fa4586fb35eb65b8a2 (patch) | |
| tree | 677f975e0870da27361a6b07b8c9d936a81c9660 /include | |
| parent | 3dafe5f6a00b765a0afee611151129d3c7ee3fd2 (diff) | |
| download | linux-f4303216f45266b949bfe7fa4586fb35eb65b8a2.tar.xz | |
can: error: specify the values of data[5..7] of CAN error frames
[ Upstream commit e70a3263a7eed768d5f947b8f2aff8d2a79c9d97 ]
Currently, data[5..7] of struct can_frame, when used as a CAN error
frame, are defined as being "controller specific". Device specific
behaviours are problematic because it prevents someone from writing
code which is portable between devices.
As a matter of fact, data[5] is never used, data[6] is always used to
report TX error counter and data[7] is always used to report RX error
counter. can-utils also relies on this.
This patch updates the comment in the uapi header to specify that
data[5] is reserved (and thus should not be used) and that data[6..7]
are used for error counters.
Fixes: 0d66548a10cb ("[CAN]: Add PF_CAN core module")
Link: https://lore.kernel.org/all/20220719143550.3681-11-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/can/error.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/uapi/linux/can/error.h b/include/uapi/linux/can/error.h index 34633283de64..a1000cb63063 100644 --- a/include/uapi/linux/can/error.h +++ b/include/uapi/linux/can/error.h @@ -120,6 +120,9 @@ #define CAN_ERR_TRX_CANL_SHORT_TO_GND 0x70 /* 0111 0000 */ #define CAN_ERR_TRX_CANL_SHORT_TO_CANH 0x80 /* 1000 0000 */ -/* controller specific additional information / data[5..7] */ +/* data[5] is reserved (do not use) */ + +/* TX error counter / data[6] */ +/* RX error counter / data[7] */ #endif /* _UAPI_CAN_ERROR_H */ |