[PATCH 2/4] can: fix IFF_ECHO example in documentation

From: Vincent Mailhol

Date: Tue Aug 04 2026 - 15:57:35 EST


The documentation suggests doing:

dev->flags = (IFF_NOARP | IFF_ECHO);

to set the IFF_ECHO flag. This is problematic because by doing so,
other potentially enabled flags would be overwritten. Furthermore,
none of the drivers do it like that.

Replace the example by:

dev->flags |= IFF_ECHO;

which is more robust and consistent with what all the drivers are doing.

Signed-off-by: Vincent Mailhol <mailhol@xxxxxxxxxx>
---
Documentation/networking/can.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/networking/can.rst b/Documentation/networking/can.rst
index 536ff411da1d..fbd0d501ea4e 100644
--- a/Documentation/networking/can.rst
+++ b/Documentation/networking/can.rst
@@ -1126,7 +1126,7 @@ e.g. of tty devices. In this case the driver flag IFF_ECHO has to be
set to prevent the PF_CAN core from locally echoing sent frames
(aka loopback) as fallback solution::

- dev->flags = (IFF_NOARP | IFF_ECHO);
+ dev->flags |= IFF_ECHO;


CAN Controller Hardware Filters

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2.54.0