From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 11 Sep 2018 11:37:25 +0200 From: Lukasz Majewski To: Linus Walleij Message-ID: <20180911113725.5d91b945@jawa> In-Reply-To: References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/YxXvblU3AsRXkNJ13QQUifZ"; protocol="application/pgp-signature" Cc: Ksummit-discuss@lists.linuxfoundation.org, Jonas Jensen , Alexander Sverdlin Subject: Re: [Ksummit-discuss] [MAINTAINERS SUMMIT] Deprecation / Removal of old hardware support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --Sig_/YxXvblU3AsRXkNJ13QQUifZ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Linus, > Including Alexander Sverdlin, Lukasz Majewski and Jonas > Jensen here, they may or may not be able to share some of > their industrial IoT experience. (Contract terms with vendors > may make it necessary to stay silent sometimes.) Thank you for putting me on CC. >=20 > On Mon, Sep 10, 2018 at 11:41 PM Arnd Bergmann wrote: > > On Mon, Sep 10, 2018 at 5:35 PM Linus Walleij > > wrote: =20 >=20 > > > My ARMv4 is another example, but I can point at new devices > > > beging deployed as we speak, using that ISA, even though it is > > > from 1999. So it has many active users (and maintainers). =20 > > > > Note that even though gcc is dropping ARMv4 support from new > > compilers, you can still use old toolchains, and there are tricks to > > make ARMv4T binary code work on ARMv4. However, if gcc > > ever stops supporting ARMv4T, this becomes a problem. My guess > > is that will take another 10 years though, and we might have > > removed some or all of the individual ARMv4 platforms by then. =20 >=20 > ARMv4 is becoming a trouble, not that it is hard to maintain, > actually we're on top of things there. The problem is that among > the FA526 systems from Faraday and the ARMv4T in EP93xx > there are very serious IoT deployments that have been going > on for soon 15 years and continuing. The ARMv4T shall be supported. The 15 years may be a bare minimum for some "heavy duty/industrial" systems... It may happen that the same HW (certified already) will be used for 30+ years (with the SW BSP replaced a few times). >=20 > New MOXA ART ARMv4 FA526 systems are being deployed > in buildings across the planet as we speak. They just replaced > one in the office block where I sit, that is how I got to know. >=20 > These are mostly for ventilation and > similar systems but also heavy duty from Liebherr controlling > unspecified hydraulic systems. The ventilation systems are > definately Internet-connected, I don't know about the others. The "unspecified hydraulic systems" do have a way to update the SW (which is already done). >=20 > These pose an increasing security threat, and for that reason > I personally feel it is irresponsible to remove the option to > create new kernels and upgrade these devices. Frankly speaking the possibility to have the new kernel in a relatively easy (and cheap) way was a strong motivator to add support to mainline. >=20 > I think for depreciation one has to be aware that some archs > used in IoT deployments have life cycles of 20-30 or more years, > whereas some tablet or handset SoCs may be something like > 5 years maximum before maintainers get annoyed that you > even use them. >=20 > Sometimes I get the feeling that people focused on desktops > or servers suffer from velocitate (speed blindness) and think > everybody is like them. (Well don't we all.) I do must agree here. In general ARM9 (v4T) will stay with us for a long, long time. In the kernel community we pose a lot of attention to security (for example the prompt reaction on meltdown/spectre), but in the same time we tend to forget about the "long lived" devices and force their maintainers to use 2.6.x kernels..... (or even 2.4.x). >=20 > With all the hoopla about IoT in the business right now since > a year or two back, the question of their extremely long life > cycle and effect on development has not really been > considered AFAICT those are some of the most important > systems to keep maintained. +1 >=20 > Yours, > Linus Walleij Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de --Sig_/YxXvblU3AsRXkNJ13QQUifZ Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAluXjNUACgkQAR8vZIA0 zr1MHQf9HEqIFzJCkLrJatzop1G1CmMj79Na2Xi4okPTC1EGyJX++fDNKKAvFibg dm1RAWrWr/lI+vk2JcldpU6iwoXMvDd5xEpkqlM1Xvi32Ff3yPe7DkSJJpabn9Xl C5gzzapyhsMfRxmaEBQNVjeSl4B1BEYfsgJE3NqSPY6U8k3vJ56hLypq4Mo0ifhl ITHn+1WxWaMvra8Dw3rE9CC2IaALWa3py8qcPrjIKUS/apjNzXpxcDNw/Qutbvjb ftS0xPRy2PyibMX5HcX+aF7T4Q0ynn3Mj8uGhvrBT25osWhZ3t3TA1mBjtsLpqTG 1g8CYgpgcBgGTYCFlDSIaCsa2Dgv3A== =VI1d -----END PGP SIGNATURE----- --Sig_/YxXvblU3AsRXkNJ13QQUifZ--