Hi Artur,
On Sat, Feb 17, 2024 at 08:02:47PM +0100, Artur Weber wrote:
> The stock bootloader on the Samsung Galaxy Tab 3 8.0 provides an
> incorrect available memory range over ATAG_MEM. Limit the usable
> memory in the DTS to prevent it from doing so, without having to
> disable ATAG support.
>
> Signed-off-by: Artur Weber <aweber.kernel@xxxxxxxxx>
> ---
> arch/arm/boot/dts/samsung/exynos4212-tab3.dtsi | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm/boot/dts/samsung/exynos4212-tab3.dtsi b/arch/arm/boot/dts/samsung/exynos4212-tab3.dtsi
> index e5254e32aa8f..9bc05961577d 100644
> --- a/arch/arm/boot/dts/samsung/exynos4212-tab3.dtsi
> +++ b/arch/arm/boot/dts/samsung/exynos4212-tab3.dtsi
> @@ -45,6 +45,12 @@ chosen {
> /* Default S-BOOT bootloader loads initramfs here */
> linux,initrd-start = <0x42000000>;
> linux,initrd-end = <0x42800000>;
> +
> + /*
> + * Stock bootloader provides incorrect memory size in ATAG_MEM;
> + * override it here
> + */
> + linux,usable-memory-range = <0x40000000 0x3fc00000>;
Maybe it would make sense to set the memory reg to
<0x40000000 0x60000000> (1.5 GiB) and move the comment about last
512(/516) MiB being weird/broken here instead. It looks a bit weird
that the memory range and usable-memory-range are identical, and device tree
should describe hardware, which technically has 1.5 GiB RAM.
>From a functional point of view it does not really matter, so in any case:
Reviewed-by: Henrik Grimler <henrik@xxxxxxxxxx>
> };
>
> firmware@204f000 {
>
> ---
> base-commit: 0f1dd5e91e2ba3990143645faff2bcce2d99778e
> change-id: 20240217-tab3-limit-usable-memory-range-1d1ffa8dc44d
>
> Best regards,
> --
> Artur Weber <aweber.kernel@xxxxxxxxx>
>
