Date: Wed, 09 Dec 1998 12:19:47 +0900 From: Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp> To: Gregory Bond <gnb@itga.com.au> Cc: current@FreeBSD.ORG, yokota@zodiac.mech.utsunomiya-u.ac.jp Subject: Re: Another keyboard freeze Message-ID: <199812090319.MAA12085@zodiac.mech.utsunomiya-u.ac.jp> In-Reply-To: Your message of "Wed, 09 Dec 1998 11:51:24 %2B1100." <199812090051.LAA09328@melba.bby.com.au> References: <199812090051.LAA09328@melba.bby.com.au>
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>3.0-Current as at around 19981206 0000 UTC, running on HP KAYAK XA (PII-400). [...] >I just experienced another strange keyboard hang. I've got X3.3.3 installed >and xdm enabled in /etc/ttys so at boot it pops up an XDM on vt7 but I can >ctl-alt-Fn to get a login on other vts. > >Then something broke. Ctl-Alt-Fn stopped working (it beeped). Everything was >working fine inside X, but I couldn't get out of it. This happens when the X server either refuses to release the screen for some reason (this is unlikely), or fails to repond in defined manner during screen switching. The problem has been around for some time both in 3.0 and 2.X. The cause (bug) of the problem may be in the console driver, in the X server, or in both. The X server may be the culprit when you cannot switch away from the X session to a vty. In contrast, the console driver must be at fault if you are still unable to switch between vtys after the X server is terminated. >Eventually, I killed the >xdm and dropped back to vt0. At that point I was stuffed: "ordinary" keys >produced no effect at all, and any of the Alt-Fn keys just produced a beep. >Only way out was the three-finger salute. The one thing I know is that the XFree86 server somehow does not respond to the screen switching protocol at some point in the server reset. You may reprodude this by doing the following: 1. Run xdm on host A. Allow access from host B. 2. Start the X server on host B by: X -query A 3. You will see the login window (for host B) on host B. Login to host A via this. You are now in a X session on host A showing windows on host B's X server. 4. On host B, switch away from the X server to a vty by pressing Ctl-Alt-Fn. 5. Login to host A from host A's X server or host A's vty. 6. And kill the X session started in 3. This will make xdm to reset the X server on host B and diplay a new login window on host B. Observe the host B; the X server was in the background and you were seeing a vty on host B's display. But now, the X server has come to the foreground automatically! And it is very likely that you cannot switch away from this X server. You get beep sound when you press Ctl-Alt-Fn on host B. Time to review screen switching code in syscons and XFree86 yet again... Kazu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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