From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel@ffwll.ch (Daniel Vetter) Date: Mon, 18 Jun 2018 09:43:20 +0200 Subject: [PATCH 1/3] drm: mxsfb: Change driver.name to mxsfb-drm In-Reply-To: <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> <6995fa4b-47a9-887b-5e4f-4284ca6a2c79@gmail.com> Message-ID: <20180618074320.GS3438@phenom.ffwll.local> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Jun 16, 2018 at 01:32:44AM +0200, Marek Vasut wrote: > 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. Yeah agreed, imo the proper fix here would be to either update the dts for the affected boards and/or make mxsfb accept the old dt bindings for backwards compat. Artificially extending the life of the fbdev drivers seems silly. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch