Function es58x_fd_rx_event() invokes the es58x_check_msg_len() macro:
| ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len);
While doing so, it dereferences an uninitialized
variable: *rx_event_msg.
This is actually harmless because es58x_check_msg_len() only uses
preprocessor macros (sizeof() and __stringify()) on
*rx_event_msg. c.f. [1].
Nonetheless, this pattern is confusing so the lines are reordered to
make sure that rx_event_msg is correctly initialized.
This patch also fixes a false positive warning reported by cppcheck:
| cppcheck possible warnings: (new ones prefixed by >>, may not be real problems)
|
| In file included from drivers/net/can/usb/etas_es58x/es58x_fd.c:
| >> drivers/net/can/usb/etas_es58x/es58x_fd.c:174:8: warning: Uninitialized variable: rx_event_msg [uninitvar]
| ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len);
| ^
[1] https://elixir.bootlin.com/linux/v5.16/source/drivers/net/can/usb/etas_es58x/es58x_core.h#L467
Link: https://lore.kernel.org/all/20220306101302.708783-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In [1], we introduced a set of units in linux/can/bittiming.h. Since
then, generic SI prefixes were added to linux/units.h in [2]. Those
new prefixes can perfectly replace CAN specific ones.
This patch replaces all occurrences of the CAN units with their
corresponding prefix (from linux/units) and the unit (as a comment)
according to below table.
CAN units SI metric prefix (from linux/units) + unit (as a comment)
------------------------------------------------------------------------
CAN_KBPS KILO /* BPS */
CAN_MBPS MEGA /* BPS */
CAM_MHZ MEGA /* Hz */
The definition are then removed from linux/can/bittiming.h
[1] commit 1d7750760b ("can: bittiming: add CAN_KBPS, CAN_MBPS and
CAN_MHZ macros")
[2] commit 26471d4a6c ("units: Add SI metric prefix definitions")
Link: https://lore.kernel.org/all/20211124014536.782550-1-mailhol.vincent@wanadoo.fr
Suggested-by: Jimmy Assarsson <extja@kvaser.com>
Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
ISO 11898-1 specifies in section 11.3.3 "Transmitter delay
compensation" that "the configuration range for [the] SSP position
shall be at least 0 to 63 minimum time quanta."
Because SSP = TDCV + TDCO, it means that we should allow both TDCV and
TDCO to hold zero value in order to honor SSP's minimum possible
value.
However, current implementation assigned special meaning to TDCV and
TDCO's zero values:
* TDCV = 0 -> TDCV is automatically measured by the transceiver.
* TDCO = 0 -> TDC is off.
In order to allow for those values to really be zero and to maintain
current features, we introduce two new flags:
* CAN_CTRLMODE_TDC_AUTO indicates that the controller support
automatic measurement of TDCV.
* CAN_CTRLMODE_TDC_MANUAL indicates that the controller support
manual configuration of TDCV. N.B.: current implementation failed
to provide an option for the driver to indicate that only manual
mode was supported.
TDC is disabled if both CAN_CTRLMODE_TDC_AUTO and
CAN_CTRLMODE_TDC_MANUAL flags are off, c.f. the helper function
can_tdc_is_enabled() which is also introduced in this patch.
Also, this patch adds three fields: tdcv_min, tdco_min and tdcf_min to
struct can_tdc_const. While we are not convinced that those three
fields could be anything else than zero, we can imagine that some
controllers might specify a lower bound on these. Thus, those minimums
are really added "just in case".
Comments of struct can_tdc and can_tdc_const are updated accordingly.
Finally, the changes are applied to the etas_es58x driver.
Link: https://lore.kernel.org/all/20210918095637.20108-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The es581_tx_can_msg() does below cast:
| tx_can_msg = (struct es581_4_tx_can_msg *)
| &es581_4_urb_cmd->bulk_tx_can_msg.tx_can_msg_buf[msg_len - 1];
The -1 offset is to skip the first member of struct
es581_4_tx_can_msg. However, es581_4_urb_cmd already has a raw_msg
field which can be used instead without the use of an offset
calculation.
The function es58x_fd_tx_can_msg() is also modified to mirror
es581_tx_can_msg().
Link: https://lore.kernel.org/r/20210628155420.1176217-7-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
