From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Hanselmann Subject: Re: Hang in uart_block_til_ready() Date: Sun, 2 Apr 2006 17:17:39 +0200 Message-ID: <20060402151739.GA402@hansmi.ch> References: <20060402135138.GC2954@hansmi.ch> <20060402143827.GA3565@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" Return-path: Received: from hansmi.home.forkbomb.ch ([213.144.146.165]:10013 "EHLO hansmi.home.forkbomb.ch") by vger.kernel.org with ESMTP id S1750819AbWDBPRl (ORCPT ); Sun, 2 Apr 2006 11:17:41 -0400 Content-Disposition: inline In-Reply-To: <20060402143827.GA3565@flint.arm.linux.org.uk> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Russell King Cc: linux-serial@vger.kernel.org --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello Russell On Sun, Apr 02, 2006 at 03:38:27PM +0100, Russell King wrote: > On Sun, Apr 02, 2006 at 03:51:38PM +0200, Michael Hanselmann wrote: > > I've discovered a problem where I'm not sure wether it's an error in the > > kernel or in the hardware. > It's neither - it's a bug in your test program. If you want "callout" > semantics, open the port using O_NONBLOCK mode. I've now patched screen(1) and it works, but one thing is amazing me. The other computer I wrote about has the serial console on ttyS0 and starting screen(1) on the serial console works. Here's the relevant strace part: screen-strace:open("/dev/ttyS0", O_RDWR|O_NONBLOCK) =3D 3 screen-strace.23801:open("/dev/ttyS0", O_RDWR) =3D 3 This doesn't work on the HP box with the serial console on ttyS2. After adding O_NONBLOCK, it works. Here's the strace: screen-strace:open("/dev/ttyS2", O_RDWR|O_NONBLOCK) =3D 3 screen-strace.31830:open("/dev/ttyS2", O_RDWR|O_NONBLOCK) =3D 3 Am I going correct that this is a bug in screen(1) and it only works on the first box by some mysterious reason? Mabye some timing issue? Thanks, Michael --=20 Gentoo Linux developer, http://hansmi.ch/, http://forkbomb.ch/ --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFEL+sT6J0saEpRu+oRAn+4AJ94evFRc3ahs7yUxgzq/5O1rxJrUACeNJVl 9Xga+rRT57jVpXKY+UkHpPE= =QcPi -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd--