Hi Jagan, On Wed, Jun 7, 2023 at 8:43 AM Jagan Teki <ja...@amarulasolutions.com> wrote: > > On Wed, Jun 7, 2023 at 12:01 PM Dario Binacchi > <dario.binac...@amarulasolutions.com> wrote: > > > > Add support to Rocktech RK043FN48H display on stm32f746-disco board. > > > > Signed-off-by: Dario Binacchi <dario.binac...@amarulasolutions.com> > > --- > > > > (no changes since v1) > > > > arch/arm/boot/dts/stm32f746-disco.dts | 51 +++++++++++++++++++++++++++ > > 1 file changed, 51 insertions(+) > > > > diff --git a/arch/arm/boot/dts/stm32f746-disco.dts > > b/arch/arm/boot/dts/stm32f746-disco.dts > > index c11616ed5fc6..cda423b6a874 100644 > > --- a/arch/arm/boot/dts/stm32f746-disco.dts > > +++ b/arch/arm/boot/dts/stm32f746-disco.dts > > @@ -60,10 +60,41 @@ memory@c0000000 { > > reg = <0xC0000000 0x800000>; > > }; > > > > + reserved-memory { > > + #address-cells = <1>; > > + #size-cells = <1>; > > + ranges; > > + > > + linux,cma { > > + compatible = "shared-dma-pool"; > > + no-map; > > + size = <0x80000>; > > + linux,dma-default; > > + }; > > + }; > > This looks unrelated to display enablement, isn't it?
Without the "reserved-memory" node, it is not possible to allocate memory for the framebuffer. I got this error: stm32-display 40016800.display-controller: [drm] *ERROR* failed to allocate buffer with size 139264 Thanks and regards, Dario > > Jagan. -- Dario Binacchi Senior Embedded Linux Developer dario.binac...@amarulasolutions.com __________________________________ Amarula Solutions SRL Via Le Canevare 30, 31100 Treviso, Veneto, IT T. +39 042 243 5310 i...@amarulasolutions.com www.amarulasolutions.com