From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH 1/3] drm: mxsfb: Change driver.name to mxsfb-drm Date: Sat, 16 Jun 2018 01:32:44 +0200 Message-ID: <6995fa4b-47a9-887b-5e4f-4284ca6a2c79@gmail.com> References: <47ea7572011735b68a8a70f0e11bdf00cb2fd86a.1529091248.git.leonard.crestez@nxp.com> <07be6d9a85b6be655fc2b084be81d8bf9715b57a.camel@nxp.com> <638457fd-85da-8fec-d146-517c43f71813@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Leonard Crestez , "festevam@gmail.com" , "stefan@agner.ch" , "marex@denx.de" , "shawnguo@kernel.org" Cc: "devicetree@vger.kernel.org" , "linux-fbdev@vger.kernel.org" , "marcofrk@gmail.com" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , dl-linux-imx , "kernel@pengutronix.de" , Fabio Estevam , "linux-arm-kernel@lists.infradead.org" , "l.stach@pengutronix.de" List-Id: devicetree@vger.kernel.org On 06/16/2018 12:42 AM, Leonard Crestez wrote: > On Fri, 2018-06-15 at 23:36 +0200, Marek Vasut wrote: >> On 06/15/2018 10:58 PM, Leonard Crestez wrote: >>> On Fri, 2018-06-15 at 16:47 -0300, Fabio Estevam wrote: >>>> On Fri, Jun 15, 2018 at 4:43 PM, Leonard Crestez >>>> wrote: > >>>>> The FBDEV driver uses the same name and both can't be registered at the >>>>> same time. Fix this by renaming the drm driver to mxsfb-drm >>>> >>>> Stefan sent the same patch a few days ago: >>> >>> In that thread there is a proposal for removing the old fbdev/mxsfb >>> driver entirely. >>> >>> That would break old DTBs, isn't this generally considered bad? Also, >>> are we sure the removal of fbdev/mxsfb wouldn't lose any features? >>> >>> What my series does is make both drivers work with the same kernel >>> image and turns the choice into a board-level dtb decision. Supporting >>> everything at once seems desirable to me and it allows for a very >>> smooth upgrade path. >> >> Having two drivers in the kernel with different set of bugs is always bad. >> >>> The old driver could be removed later, after all users are converted. >> >> Both drivers were in for long enough already. And let's be realistic, >> how many MX23/MX28 users of old DTs with new kernels are there who >> cannot update the DT as well ? > > Grepping for "display =" in arch/arm/boot/dts/imx* I see that old > bindings are also used by 3rd-party boards for imx6/7: > * imx6sx-nitrogen6sx > * imx6ul-geam > * imx6ul-isiot > * imx6ul-opos6uldev > * imx6ul-pico-hobbit > * imx6ul-tx6ul > * imx7d-nitrogen7 Er, yes, a handful of boards which could be updated :) > Converting everything might be quite a bit of work, and explicitly > supporting old bindings is also work. Does adding support for old bindings justify the effort invested ? I doubt so, it only adds more code to maintain. > It is very confusing that there is a whole set of displays for imx6/7 > which are supported by upstream but only with a non-default config. > While it is extremely common in the embedded field to have custom > configs the default one in the kernel should try to "just work". > > Couldn't this patch series be considered a bugfix? It was also > surprisingly small. I think it's just a workaround which allows you to postpone the real fix, and I don't like that. -- Best regards, Marek Vasut