On Sat, Dec 17, 2022 at 07:38:06PM +0100, Uwe Kleine-König wrote: > On Fri, Dec 16, 2022 at 05:57:58PM -0600, Rob Herring wrote: > > On Fri, Dec 16, 2022 at 06:50:04PM +0100, Uwe Kleine-König wrote: > > > Hello, > > > > > > Changes since v2: > > > > > > - added allOf as Krzysztof requested > > > - reworked driver based on Philipp's comments > > > (improved error handling, different selects, moved driver to a subdirectory, > > > header sorting, drm_err instead of DRM_ERROR, inlined > > > imx_lcdc_check_mode_change, make use of dev_err_probe()) > > > > > > Krzysztof also pointed out that we're now having two compatibles for a > > > single hardware. Admittedly this is unusual, but this is the chance that > > > the (bad) compatible identifier imx21-fb gets deprecated. The hardware > > > is called LCDC and only the linux (framebuffer) driver is called imxfb. > > > > The problem is you can't have firmware (with the DTB) that supports > > both. Well, you can if you want to have some firmware setting that > > selects which one. Otherwise, it's really an OS problem to decide what > > to use. > > I don't understand what you intend to say here. The same applies if the > compatible is the same for both binding alternatives, isn't it? Only if you have both nodes in the DT and both enabled. But 2 enabled nodes at the same address is also a dtc warning, so I was assuming you didn't do that. > Do you consider a firmware problem better or an OS problem? The OS created the problem, so they get to keep it. But a PC BIOS is full of OS compatibility switches, so... In the end, it's the platforms' decision really. I just want what the implications of having 2 compatibles are to be understood. Rob