Re: [PATCH] ARM: dts: exynos4212-tab3: limit usable memory range

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Artur Weber <aweber.kernel@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Alim Akhtar <alim.akhtar@samsung.com>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
	~postmarketos/upstreaming@lists.sr.ht
Subject: Re: [PATCH] ARM: dts: exynos4212-tab3: limit usable memory range
Date: Thu, 22 Feb 2024 16:55:02 +0100	[thread overview]
Message-ID: <d41b7281-5f44-4de0-9ea6-5dcae26ac295@linaro.org> (raw)
In-Reply-To: <5d67441e-df61-4894-ba52-2bed8a1143d6@linaro.org>

On 21/02/2024 09:26, Krzysztof Kozlowski wrote:
> On 19/02/2024 20:49, Artur Weber wrote:
>> On 19.02.2024 08:44, Krzysztof Kozlowski wrote:
>>> On 17/02/2024 20:02, 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@gmail.com>
>>>> ---
>>>>   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>;
>>>
>>> Applied and dropped:
>>>   chosen: linux,usable-memory-range:0: [4611686019496935424] is too short
>>
>> This seems to be a binding issue; the DT schema expects a 64-bit memory 
>> address and size, and doesn't allow a 32-bit range. I've tested the DTS 
>> on my device and this property seems to be handled fine, so I think this 
>> should allow 32-bit values as well.
> 
> Regardless where is the issue: please test before sending.
> 
>>
>> I've opened a PR[1] against devicetree-org/dt-schema (where the schema 
>> for the chosen node is stored) to try and fix this. If my approach is 
>> incorrect, feel free to comment there as well.
> 
> 
> According to Rob's comments, the DTS is the issue.

With updated dtschema I still see the same warning. Is something else
missing?

Best regards,
Krzysztof

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel