[PATCH] [RFC] drm: rcar-du: keep temporary dtb files around during build

[Arnd Bergmann]

On Fri, Mar 16, 2018 at 2:39 AM,  <Frank.Rowand at sony.com> wrote:
> On Thursday, March 15, 2018 8:37 AM, Arnd Bergmann [mailto:arnd at arndb.de]  wrote:
>>
>> The *.dtb and *.dtb.S files get removed by 'make' during the build
>> process,
>> and later seem to be missed during the 'modpost' stage:
>>
>> rm drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7795.dtb
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7791.dtb
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7791.dtb.S
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7795.dtb.S
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7790.dtb.S
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7793.dtb
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7796.dtb
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7790.dtb
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7796.dtb.S
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7793.dtb.S
>> WARNING: could not open
>> drivers/gpu/drm/rcar-du/rcar_du_of_lvds_r8a7790.dtb.S: No such file or
>> directory
>>
>> As a workaround, this adds all those files to the 'extra-y' target list,
>> but that's really ugly. Any ideas for a better fix?
>
> Does this work for you (untested, but the way it is done in
> drivers/of/unittest-data/Makefile):
>
> .PRECIOUS: \
>         $(obj)/%.dtb.S \
>         $(obj)/%.dtb

Yes, that works and looks much better than my version.

      Arnd