On 7/14/2017 4:37 PM, Petr Mladek wrote: > On Fri 2017-07-14 14:57:45, Fabio M. Di Nitto wrote: >> Hi Petr, >> >> On 7/14/2017 2:51 PM, Petr Mladek wrote: >>> Some early consoles have code and data in the init section. It makes some >>> sense but this might cause problems when they are not replaced by >>> the real console in time. The two patches fix the safequard and >>> help to avoid the problems. >>> >>> I though about removing keep_bootcon option completely. But it is useful >>> at least for now. >> >> Let´s just keep in mind that keep_bootcon was introduced only to debug >> issues (read crashes or hangs) that could happen between disabling >> bootconsole and enabling the real console. It shouldn´t be used for >> anything else really. > > This was my initial replay as well. But then I realized that > it was a bad idea to use a freed code and data to debug any other > issue. It would just create crazy issues on its own. Perhaps some changes that were made later in the code introduced this behavior. I honestly didn´t check. It´s been just so long ago :-) > > I tried to google 'keep_bootcon'. It found several links to strange > crashes related to this option. Maybe I was not patient enough but > I did not find any page where this option was suggested and helped. It´s in Documentation/admin-guide/kernel-parameters.txt. It´s also rare that consoles are not working or something is crashing in that small window, so I am not entirely surprised that there are few to none references of users using it. > > I still think that the option makes some sense but only when > it does not cause more breakages on its own. agreed. Cheers Fabio > >> If the new code can replace keep_bootcon, by all mean, go for it :-) > > keep_bootcon stays usable for most early consoles. We print a warning > when an unusable console is disabled too early. Also there is a > comment how to fix it. > > Best Regards, > Petr > -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
