Message ID | 20200421231403.199217-1-pcc@google.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | arm64: dts: fast models: Fix FVP video RAM size | expand |
On Tue, Apr 21, 2020 at 4:14 PM Peter Collingbourne <pcc@google.com> wrote: > > According to the Fast Models Reference Manual, FVP has 32MB of video > RAM starting at physical address 0x18000000, but the DTS only declares > 8MB. Fix that. I may have sent this out too soon. After further debugging I discovered that Android requires more than the designated 32MB of video RAM. It turns out that FVP supports DMA between the graphics device and DRAM. Therefore I propose to change the DTS for FVP to use a dynamic allocation of 256MB of DRAM for video RAM. I will send a patch to do this shortly. With that (together with [1]) I can boot Android with graphical output over DRM. Peter [1] https://patchwork.kernel.org/patch/11506759/ Peter > > Signed-off-by: Peter Collingbourne <pcc@google.com> > --- > arch/arm64/boot/dts/arm/fvp-base-revc.dts | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/boot/dts/arm/fvp-base-revc.dts b/arch/arm64/boot/dts/arm/fvp-base-revc.dts > index 66381d89c1ce..72c018188c40 100644 > --- a/arch/arm64/boot/dts/arm/fvp-base-revc.dts > +++ b/arch/arm64/boot/dts/arm/fvp-base-revc.dts > @@ -105,9 +105,9 @@ reserved-memory { > > /* Chipselect 2,00000000 is physically at 0x18000000 */ > vram: vram@18000000 { > - /* 8 MB of designated video RAM */ > + /* 32 MB of designated video RAM */ > compatible = "shared-dma-pool"; > - reg = <0x00000000 0x18000000 0 0x00800000>; > + reg = <0x00000000 0x18000000 0 0x02000000>; > no-map; > }; > }; > -- > 2.26.1.301.g55bc3eb7cb9-goog >
On Fri, Apr 24, 2020 at 1:30 AM Peter Collingbourne <pcc@google.com> wrote: > On Tue, Apr 21, 2020 at 4:14 PM Peter Collingbourne <pcc@google.com> wrote: > > > > According to the Fast Models Reference Manual, FVP has 32MB of video > > RAM starting at physical address 0x18000000, but the DTS only declares > > 8MB. Fix that. > > I may have sent this out too soon. After further debugging I > discovered that Android requires more than the designated 32MB of > video RAM. > > It turns out that FVP supports DMA between the graphics device and > DRAM. Therefore I propose to change the DTS for FVP to use a dynamic > allocation of 256MB of DRAM for video RAM. I will send a patch to do > this shortly. With that (together with [1]) I can boot Android with > graphical output over DRM. Hey that is quite an accomplishment :D When I started to convert the ARM Reference designs to use the DRM PL111 driver we didn't know if we'd find any real-world use case for it other than being a good role model and running some old boards. Now it is suddenly really useful. Thanks! Linus Walleij
diff --git a/arch/arm64/boot/dts/arm/fvp-base-revc.dts b/arch/arm64/boot/dts/arm/fvp-base-revc.dts index 66381d89c1ce..72c018188c40 100644 --- a/arch/arm64/boot/dts/arm/fvp-base-revc.dts +++ b/arch/arm64/boot/dts/arm/fvp-base-revc.dts @@ -105,9 +105,9 @@ reserved-memory { /* Chipselect 2,00000000 is physically at 0x18000000 */ vram: vram@18000000 { - /* 8 MB of designated video RAM */ + /* 32 MB of designated video RAM */ compatible = "shared-dma-pool"; - reg = <0x00000000 0x18000000 0 0x00800000>; + reg = <0x00000000 0x18000000 0 0x02000000>; no-map; }; };
According to the Fast Models Reference Manual, FVP has 32MB of video RAM starting at physical address 0x18000000, but the DTS only declares 8MB. Fix that. Signed-off-by: Peter Collingbourne <pcc@google.com> --- arch/arm64/boot/dts/arm/fvp-base-revc.dts | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)