Date: Tue, 14 Apr 2009 18:00:20 +0200 From: Fabian Keil <freebsd-listen@fabiankeil.de> To: Maksim Yevmenkin <emax@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: svn commit: r190857 - head/sys/dev/kbdmux Message-ID: <20090414180020.34b97378@fabiankeil.de> In-Reply-To: <bb4a86c70904121000p60b48632q22a5b92fc791f4f8@mail.gmail.com> References: <200904082052.n38KqU9p075633@svn.freebsd.org> <20090412170335.5a8a3169@fabiankeil.de> <bb4a86c70904121000p60b48632q22a5b92fc791f4f8@mail.gmail.com>
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[-- Attachment #1 --] Maksim Yevmenkin <emax@freebsd.org> wrote: > On Sun, Apr 12, 2009 at 8:03 AM, Fabian Keil > <freebsd-listen@fabiankeil.de> wrote: > > Maksim Yevmenkin <emax@FreeBSD.org> wrote: > > > >> Author: emax > >> Date: Wed Apr 8 20:52:30 2009 > >> New Revision: 190857 > >> URL: http://svn.freebsd.org/changeset/base/190857 > >> > >> Log: > >> Undo SVN rev 183283 > >> > >> Do not use Giant for kbdmux(4) locking. This is wrong and apparently > >> causing more problems than it solves. This will re-open the issue > >> where interrupt handlers may race with kbdmux(4) in polling mode. > >> Typical symptoms include (but not limited to) duplicated and/or > >> missing characters when low level console functions (such as gets) > >> are used while interrupts are enabled (for example geli password > >> prompt, mountroot prompt etc.) > >> > >> MFC after: 3 days > >> > >> Modified: > >> head/sys/dev/kbdmux/kbdmux.c [...] > > Not even enabling the "visible characters" option helps > > because obviously backspace is broken too. > > if you do not need kbdmix(4) you might just want to disable it on your > system. i think it should help with your particular problem. Removing kbdmux from the kernel does indeed work around the problem. > > Before theses locks were introduces I worked around the problem > > with this gets() hack (which forced me to reduce the key entropy): > > http://www.fabiankeil.de/sourcecode/freebsd/gets-no-duplicates.diff > > and now I will simply revert your commit locally, but I assume I'm > > not the only geli user who prefers to be able to boot the system > > without local patches. > > if your primary keyboard is atkbd(4), you might want to try the > following patch. it is completely untested (i did not even compile > it), so be warned ... > > Index: atkbd.c > =================================================================== > --- atkbd.c (revision 190905) > +++ atkbd.c (working copy) > @@ -476,7 +476,7 @@ > static int > atkbd_intr(keyboard_t *kbd, void *arg) > { > - atkbd_state_t *state; > + atkbd_state_t *state = (atkbd_state_t *)kbd->kb_data; > int delay[2]; > int c; > > @@ -485,7 +485,6 @@ > * The keyboard was not detected before; > * it must have been reconnected! > */ > - state = (atkbd_state_t *)kbd->kb_data; > init_keyboard(state->kbdc, &kbd->kb_type, > kbd->kb_config); > KBD_FOUND_DEVICE(kbd); > @@ -497,6 +496,9 @@ > } > > if (KBD_IS_ACTIVE(kbd) && KBD_IS_BUSY(kbd)) { > + if (state->ks_polling) > + return 0; > + > /* let the callback function to process the input */ > (*kbd->kb_callback.kc_func)(kbd, KBDIO_KEYINPUT, > kbd->kb_callback.kc_arg); > It compiles alright but once the system is running the keyboard no longer works at all. I tested the patch with kbdmux already disabled, but I assume it doesn't make a difference. Anyway, I don't need kbdmux, so having to remove it is no problem. Thanks a lot. Fabian [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.11 (FreeBSD) iEYEARECAAYFAknksxoACgkQBYqIVf93VJ30rQCgxRiQdlHRmD/kzVSgNkua7Y8a 9OMAoIesdVWcFymsf+1L+wyHOXyBerhE =7Uvq -----END PGP SIGNATURE-----help
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