On Tue, Jun 28, 2022 at 04:30:10PM +0200, Christian Marangi wrote: > commit 386228c694bf1e7a7688e44412cb33500b0ac585 upstream. > > It was discovered that the Documentation lacks of a fundamental detail > on how to correctly change the MAX_FRAME_SIZE of the switch. > > In fact if the MAX_FRAME_SIZE is changed while the cpu port is on, the > switch panics and cease to send any packet. This cause the mgmt ethernet > system to not receive any packet (the slow fallback still works) and > makes the device not reachable. To recover from this a switch reset is > required. > > To correctly handle this, turn off the cpu ports before changing the > MAX_FRAME_SIZE and turn on again after the value is applied. > > Fixes: f58d2598cf70 ("net: dsa: qca8k: implement the port MTU callbacks") > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx> > Link: https://lore.kernel.org/r/20220621151122.10220-1-ansuelsmth@xxxxxxxxx > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > [ backport: fix conflict using the old port_sts struct instead of bitmap ] > --- > drivers/net/dsa/qca8k.c | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) This only applied to 5.15.y and 5.18.y, what about 5.10.y? Please give us a hint as to what kernel(s) a backport is for when sending them. thanks, greg k-h