On 21/1/6 15:33, Sergey Senozhatsky wrote: > On (21/01/06 14:46), chenzhen wrote: >> Since 54f19b4a6(tty/serial/8250: Touch NMI watchdog in wait_for_xmitr), >> serial8250 >> will always touch watchdog in write and wait_for_xmitr. However, serial8250 >> may >> become low speed thus take a long time to print. In this process, nmi and >> soft >> watchdog on current CPU will be invalid. >> >> To resolve this problem, add a cmdline option "tty_watchdog_enable" to >> control >> the touchdog in serial8250. > Sorry, I don't understand - what does this fix? > > -ss > .
It fixes that if serial8250 is low speed on some machine, when it writes for a long time, NMI/softlockup watchdog will never bark and potential rlock will not be detected. So an option to control the touchdog in serial8250 may help. Thanks for your reply! -Zhen Chen
