From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60426) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TL7Cg-0007dY-Rj for qemu-devel@nongnu.org; Mon, 08 Oct 2012 02:52:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TL7Cc-0003QR-O6 for qemu-devel@nongnu.org; Mon, 08 Oct 2012 02:52:38 -0400 Received: from goliath.siemens.de ([192.35.17.28]:26042) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TL7Cc-0003P8-FG for qemu-devel@nongnu.org; Mon, 08 Oct 2012 02:52:34 -0400 Message-ID: <5072782E.9090707@siemens.com> Date: Mon, 08 Oct 2012 08:52:30 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <506F1934.5000002@siemens.com> <506F207A.70805@siemens.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] versatile: Push lsi initialization to the end List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: qemu-devel On 2012-10-06 04:13, Peter Maydell wrote: > On 5 October 2012 19:01, Jan Kiszka wrote: >> I'm not a fan of this either, but the alternatives are way more >> complicated. We either need to rewrite the chardev subsystem, >> specifically how mux'ed devices are registered and how the active one is >> selected. Or we need to avoid flushing "unrelated" BHs for block >> devices. Not sure of those read requests can be postponed. > > Is this a regression? If it is then the obvious answer is to back > out whatever broke it... I'm using this machine for the first time, so I cannot answer this from the top of my head. However, I don't think it can be a regression. Mux chardevs work like this: You create the backend, then you register the frontend with them, one by one. The last one registered is the first one active. It should also receive the open event of chardev. But as that open even is issued via a BH and last frontend, the serial device, arrives after the first BH flushing, things break. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux