On Thu, Oct 14, 2021 at 10:01:53AM +0200, Francesco Dolcini wrote: > Hello Greg, > > On Thu, Oct 14, 2021 at 09:33:55AM +0200, Greg Kroah-Hartman wrote: > > On Thu, Oct 14, 2021 at 09:10:52AM +0200, Francesco Dolcini wrote: > > > From: Stefan Agner <stefan@xxxxxxxx> > > > > > > If the device used as a serial console gets un/re-binded, then > > > register_console() will call imx_uart_setup_console() again. > > > Drop __init so that imx_uart_setup_console() can be safely called > > > at runtime. > > > > > > Signed-off-by: Stefan Agner <stefan@xxxxxxxx> > > > Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> > > > --- > > > drivers/tty/serial/imx.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > What commit does this "fix"? > > root@colibri-imx6ull-06746657:~# cat /sys/devices/virtual/tty/console/active > tty1 ttymxc0 > root@colibri-imx6ull-06746657:~# echo -n N > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console > root@colibri-imx6ull-06746657:~# echo -n Y > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console > > struct console ->setup is called at that time, but imx_uart_console_setup() is gone ... This specific way I described here to reproduce the issue was introduced with a3cb39d258ef serial: core: Allow detach and attach serial device for console that is kernel 5.9+ (Andy added to to:) But the original report was about bind/unbind of the uart driver, I guess this is possible since way more time. > > According to the original report from Stefan the issue is the same with unbind/bind of the console, > see https://marc.info/?l=linux-serial&m=154221779312036&w=2. > > > > Should this go to stable kernels? If so, how far back? > This is present also in 4.19 kernel, I feel like the issue is there since it is possible to unbind > a console driver (since ever considering the current LTS releases?). I could > investigate this a little bit more. > > We have this patch in our kernel branch since 3 years but for some reason we never managed to upstream it. > > > Francesco
