Messages in this thread | | | Date | Sun, 24 Nov 2019 00:02:33 +0000 | From | Sudip Mukherjee <> | Subject | Re: [PATCH v2 2/2] tty: use tty_init_dev_retry() to workaround a race condition |
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On Fri, Nov 22, 2019 at 10:11:26AM +0100, Jiri Slaby wrote: > On 22. 11. 19, 10:05, Jiri Slaby wrote: > > On 21. 11. 19, 22:01, Sudip Mukherjee wrote: > >> Hi Greg, > >> > >> On Thu, Nov 21, 2019 at 05:41:38PM +0100, Greg Kroah-Hartman wrote: > >>> On Thu, Nov 21, 2019 at 03:22:39PM +0000, Sudip Mukherjee wrote: > >>>> There seems to be a race condition in tty drivers and I could see on > >>>> many boot cycles a NULL pointer dereference as tty_init_dev() tries to
<snip>
> > > > Interferences of console vs tty code are ugly. Does it help to simply > > put tty_port_link_device to uart_add_one_port before uart_configure_port? > > Alternatively, you can try setting tty_port in uart_install by: > tty->port = &state->port.
I have not tried these. will try.
> > BTW do you see the warning from tty_init_dev: > "driver does not set tty->port. This will crash the kernel later. Fix > the driver!\n" > ? Maybe not given console is registered already, but crashes.
yes. I do see the warning but I have always assumed that the warning is because console is openend as soon as it registers and so uart_add_one_port() does not get the chance to link it. Is it not so?
-- Regards Sudip
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