On Tue, Mar 26, 2024 at 03:40:14PM +0800, liu....@h3c.com wrote: > Note that we still need to a workqueue since we cannot resync > the keyboard state from the hardirq context provided by irq_work.
I think you are missing a word between "to" and "a", right? > That must be done from task context for the calls into the input > subystem. Hence we must defer the work twice. First to safely > switch from the debug trap (NMI-like context) to hardirq and > then, secondly, to get from hardirq to the system workqueue. > > Signed-off-by: LiuYe <liu....@h3c.com> > Co-authored-by: Daniel Thompson <daniel.thomp...@linaro.org> > Signed-off-by: Daniel Thompson <daniel.thomp...@linaro.org> > > --- > V5 -> V6: Replace with a more professional and accurate answer. > V4 -> V5: Answer why schedule another work in the irq_work and not do the job > directly. > V3 -> V4: Add changelogs > V2 -> V3: Add description information > V1 -> V2: using irq_work to solve this properly. > --- > --- > drivers/tty/serial/kgdboc.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c > index 7ce7bb164..161b25ecc 100644 > --- a/drivers/tty/serial/kgdboc.c > +++ b/drivers/tty/serial/kgdboc.c > @@ -22,6 +22,7 @@ > #include <linux/module.h> > #include <linux/platform_device.h> > #include <linux/serial_core.h> > +#include <linux/irq_work.h> > > #define MAX_CONFIG_LEN 40 > > @@ -99,10 +100,17 @@ static void kgdboc_restore_input_helper(struct > work_struct *dummy) > > static DECLARE_WORK(kgdboc_restore_input_work, kgdboc_restore_input_helper); > > +static void kgdboc_queue_restore_input_helper(struct irq_work *unused) > +{ > + schedule_work(&kgdboc_restore_input_work); As this is a "two stage deferment" or something like that, it should be documented in the code exactly why this is needed and what is happening, otherwise it looks very odd. thanks, greg k-h _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport