From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by yocto-www.yoctoproject.org (Postfix, from userid 118) id E0657E00A4F; Sat, 3 Nov 2018 01:38:40 -0700 (PDT) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on yocto-www.yoctoproject.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 X-Spam-HAM-Report: * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, * medium trust * [147.11.146.13 listed in list.dnswl.org] Received: from mail1.windriver.com (mail1.windriver.com [147.11.146.13]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id AD62DE00A10 for ; Sat, 3 Nov 2018 01:38:39 -0700 (PDT) Received: from ALA-HCA.corp.ad.wrs.com ([147.11.189.40]) by mail1.windriver.com (8.15.2/8.15.1) with ESMTPS id wA38cU65014057 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Sat, 3 Nov 2018 01:38:30 -0700 (PDT) Received: from pek-khao-d2 (147.11.105.123) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server (TLS) id 14.3.408.0; Sat, 3 Nov 2018 01:38:30 -0700 Date: Sat, 3 Nov 2018 16:37:13 +0800 From: Kevin Hao To: Khem Raj Message-ID: <20181103083713.GA4438@pek-khao-d2> References: <6c9102d2-91dc-41be-3aec-ab60d4688af5@denx.de> <20181101021854.GT24227@pek-khao-d2> <13692616-30d3-1bae-71b7-1ed2373a9a61@denx.de> <20181102085916.GA31329@pek-khao-d2> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Originating-IP: [147.11.105.123] Cc: Yocto Project Subject: Re: thud, beaglebone-yocto.conf: SERIAL_CONSOLES setting X-BeenThere: yocto@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of all things Yocto Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Nov 2018 08:38:41 -0000 X-Groupsio-MsgNum: 43055 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="6TrnltStXW4iwmi0" Content-Disposition: inline --6TrnltStXW4iwmi0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 02, 2018 at 07:27:04AM -0700, Khem Raj wrote: > On Fri, Nov 2, 2018 at 2:02 AM Kevin Hao wrote: > > > > On Fri, Nov 02, 2018 at 09:01:34AM +0100, Heiko Schocher wrote: > > > Hello Kevin, > > > > > > Am 01.11.2018 um 03:18 schrieb Kevin Hao: > > > > On Wed, Oct 31, 2018 at 02:23:00PM +0100, Heiko Schocher wrote: > > > > > Hello all, > > > > > > > > > > just builded core-image-minimal with current head of thud branch = for > > > > > the beaglebone-yocto machine, with linux 4.14.x LTS "Linux versio= n 4.14.78", > > > > > installed the resulting sd card image and boot it, and get: > > > > > > > > > > INIT: Id "O0" respawning too fast: disabled for > > > > > 5 minutes > > > > > > > > > > Reason seems to be: > > > > > > > > > > meta-yocto-bsp/conf/machine/beaglebone-yocto.conf > > > > > > > > > > SERIAL_CONSOLES =3D "115200;ttyO0" > > > > > > > > > > shouldn't this be > > > > > > > > > > SERIAL_CONSOLES =3D "115200;ttyS0" > > > > > > > > > > With this fix, sd card image boot fine ... may I oversee seomthing > > > > > obvious ? > > > > > > > > No, it should be 'ttyO0'. It is set by the omap serial driver. You = can > > > > refer the following in platform_data/serial-omap.h: > > > > #define OMAP_SERIAL_NAME "ttyO" > > > > > > Yes, you are right, but I see with linux kernel 4.14.78 from > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/comm= it/?h=3Dlinux-4.14.y&id=3De7405910ca5553eae8744af4e5c03e64ee048cb1 > > > > > > and I see: > > > > > > [ 0.000000] Linux version 4.14.78 (oe-user@oe-host) (gcc version 8= =2E2.0 > > > (GCC)) #1 Thu Nov 1 10:51:09 UTC 2018 > > > [ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr= =3D10c5387d > > > [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing= instruction cache > > > [ 0.000000] OF: fdt: Machine model: TI AM335x BeagleBone Black > > > [...] > > > [ 0.362878] Serial: 8250/16550 driver, 6 ports, IRQ sharing disabl= ed > > > [ 0.365758] 44e09000.serial: ttyS0 at MMIO 0x44e09000 (irq =3D 30,= base_baud =3D 3000000) is a 8250 > > > [ 1.030465] console [ttyS0] enabled > > > > > > So definitely a ttyS0 ... > > > > OK, so you don't use the linux-yocto kernel, you must not use the Yocto= kernel > > meta either. >=20 > I dont think there is such a rule. I don't get what you mean about such a rule. I didn't say anything about th= at. I just pointed out why Heiko get stuck by that issue and how to workaround = it. > meta-yocto-bsps are meant as > references and people might want to enhance them. Of course, that is also why we are continually working on it. >=20 > The reason that you got a ttyS0 here is that you use the > > 8250_omap.c driver. But in Yocto we use the omap-serial.c driver. You c= an > > workaround this issue by enabling SERIAL_8250_OMAP_TTYO_FIXUP. > > >=20 > omap serial is obsolete why does linux-yocto keeps using it. I guess that the original reason that we use this should be something like = the comments in the omap-serial.c: * Note: This driver is made separate from 8250 driver as we cannot * over load 8250 driver with omap platform specific configuration for * features like DMA, it makes easier to implement features like DMA and * hardware flow control and software flow control configuration with * this driver as required for the omap-platform. Yes, it has been a long time since the comments were written and even befor= e the birth of the 8250_omap.c. But I am just not sure that the 8250_omap driver is mature enough so we can switch to it safely and we also don't get any se= rial issue so far. That is why we leave it as is. And it also seem that the omap= -serial.c is also enabled by default in both the multi_v7_defconfig and omap2plus_def= config in the latest kernel: $ git grep "CONFIG_SERIAL_OMAP" arch/arm/ arch/arm/configs/multi_v7_defconfig:CONFIG_SERIAL_OMAP=3Dy arch/arm/configs/multi_v7_defconfig:CONFIG_SERIAL_OMAP_CONSOLE=3Dy arch/arm/configs/omap2plus_defconfig:CONFIG_SERIAL_OMAP=3Dy arch/arm/configs/omap2plus_defconfig:CONFIG_SERIAL_OMAP_CONSOLE=3Dy But if you are pretty sure that the 8250_omap.c is mature enough and also provide more functions than omap-serial.c, please send a patch and we can definitely switch the serial driver to that. > seondly, machine config should enable both consoles ttyO0 and ttyS0 if > you know that at least one kernel is using ttyO0 Yes, this is an option to fix this issue. Do you mind send a patch? Thanks, Kevin >=20 > > Thanks, > > Kevin > > > > > > > > bye, > > > Heiko > > > > > > > > Thanks, > > > > Kevin > > > > > > > > > > > > > > bye, > > > > > Heiko > > > > > -- > > > > > DENX Software Engineering GmbH, Managing Director: Wolfgang = Denk > > > > > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Ger= many > > > > > Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@den= x.de > > > > > -- > > > > > _______________________________________________ > > > > > yocto mailing list > > > > > yocto@yoctoproject.org > > > > > https://lists.yoctoproject.org/listinfo/yocto > > > > > > -- > > > DENX Software Engineering GmbH, Managing Director: Wolfgang Denk > > > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > > > Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de > > -- > > _______________________________________________ > > yocto mailing list > > yocto@yoctoproject.org > > https://lists.yoctoproject.org/listinfo/yocto --6TrnltStXW4iwmi0 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEHc6qFoLCZqgJD98Zk1jtMN6usXEFAlvdXjkACgkQk1jtMN6u sXFTtAgAsBaH5AE+a3X6uoqgDfUZBymG/J3u+RYbR/lvcCBQ0XDqj2zrpvHjnOjy My71qrCR3uWCzm0bIcFZjQsQgEhfmSFLfoJrEOaIWZO0Q6sXov7Ba9AIFvL0Y4N8 7onJroDwDjDU8QJXI3SEPXsHDjtuxCLB9D3FHv2/xiCXVnqbr+IhmAJXAjP9tL0Q aFNLJMG7mEGFRPd+58t6iExCmcPNRAuyan2lOggVM+miXPZYQzIEd0aq6Oin+neP qCe/suex7TbCfVh7Pcz+EPWDn1UnZebuB/Nqg/Ry3H3IgQl6nu9aeApP2ZFssiVF 47svStuKCD7emRjDDgvqllROfRcI3Q== =YBLM -----END PGP SIGNATURE----- --6TrnltStXW4iwmi0--