From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N5gux-0006ZU-Di for qemu-devel@nongnu.org; Wed, 04 Nov 2009 09:32:59 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N5gur-0006W7-FN for qemu-devel@nongnu.org; Wed, 04 Nov 2009 09:32:57 -0500 Received: from [199.232.76.173] (port=49332 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N5gur-0006Vu-2B for qemu-devel@nongnu.org; Wed, 04 Nov 2009 09:32:53 -0500 Received: from fmmailgate02.web.de ([217.72.192.227]:59862) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N5guq-0007q5-Ep for qemu-devel@nongnu.org; Wed, 04 Nov 2009 09:32:52 -0500 Message-ID: <4AF18FFD.7030807@web.de> Date: Wed, 04 Nov 2009 15:30:21 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <1257258596-4556-1-git-send-email-amit.shah@redhat.com> <1257258596-4556-2-git-send-email-amit.shah@redhat.com> <1257258596-4556-3-git-send-email-amit.shah@redhat.com> <4AF063A9.7000908@siemens.com> <20091103175552.GA25029@amit-x200.redhat.com> <20091103180934.GA25423@amit-x200.redhat.com> <4AF07C37.9040904@web.de> <20091104052113.GA27028@amit-x200.redhat.com> <4AF14BDB.3050306@web.de> <20091104104847.GA27835@amit-x200.redhat.com> In-Reply-To: <20091104104847.GA27835@amit-x200.redhat.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigA754417CB8C646934DA476A4" Sender: jan.kiszka@web.de Subject: [Qemu-devel] Re: [PATCH 2/3] char: Remove special init_reset handling List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amit Shah Cc: qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigA754417CB8C646934DA476A4 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Amit Shah wrote: > On (Wed) Nov 04 2009 [10:39:39], Jan Kiszka wrote: >> Amit Shah wrote: >>> On (Tue) Nov 03 2009 [19:53:43], Jan Kiszka wrote: >>>> Amit Shah wrote: >>>>> On (Tue) Nov 03 2009 [23:25:52], Amit Shah wrote: >>>>>> On (Tue) Nov 03 2009 [18:08:57], Jan Kiszka wrote: >>>>>>> Amit Shah wrote: >>>>>>>> The initial_reset sent to chardevs doesn't do much other than se= tting >>>>>>>> a bool to true. Char devices are interested in the open event an= d >>>>>>>> that gets sent whenever the device is opened. >>>>>>> Have you checked with the monitor in all use cases (dedicated & m= uxed >>>>>>> console, stdio & SDL console, etc.)? It was introduced once to fi= x a >>>>>> I've checked with -monitor stdio, monitor in SDL and also chardevs= using >>>>>> unix sockets. >>>>>> >>>>>> I've not tried mux yet; I'll try that and report back. BTW if it e= nds up >>>>>> not working with this patch, it'd be broken in the current master = as >>>>>> well. >>>>> I tried with: >>>>> >>>>> -chardev stdio,mux=3Don,id=3Dmux -monitor chardev:mux -serial chard= ev:mux >>>>> >>>>> The monitor prompt shows up as does the serial output. >>>>> >>>>> (btw I've also tried closing and opening char devs and that works f= ine >>>>> too) >>>> That sounds good. Then something must have changed since 2970a6c943,= do >>>> you see what? >>> I think that depended on the resets being sent. I've now removed the >>> need for resets altogether. >> No, this is in fact the reason why we no longer need it: >> >> 9a1e948129 (Introduce contexts for asynchronous callbacks) >> >> As the initial reset of the char device that is marked pending on open= >> is now no longer consumed by the IDE initialization, we can actually >> drop the later regeneration via qemu_chr_initial_reset. I just hope th= is >> stays like it is... >=20 > I tested this even on a tree that doesn't have this patch. The whole things was (and maybe still is) fragile. So you have to take care what further patches with side effects you include. If you revert 9a1e948129 and remove qemu_chr_initial_reset, you get the old bug back again, ie. no prompt. >=20 > I haven't really delved deep to see why this was added earlier -- the > commit log only says very little. Plus my testing with the current tree= > works fine so I'm happy to mention these things in the commit log. I've nothing against your patch, specifically as it removes an obviously no longer needed workaround, not a feature. I just want to make sure that the current behavior is not only there by chance. Jan --------------enigA754417CB8C646934DA476A4 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkrxkAEACgkQitSsb3rl5xTAuACglddnNBNoxEauRpJojz1/hxh8 hU8An2lLDqtcib4sz+0kJN5A0eMWStMk =GBfs -----END PGP SIGNATURE----- --------------enigA754417CB8C646934DA476A4--