Re: [PATCH 2/2] arm: dts: rk356x: rock3a: disable pcie3x2

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hello Marco,

On 1/21/26 01:07, Marco Felsch wrote:
> Hi Ahmad,
> 
> On 26-01-20, Ahmad Fatoum wrote:
>> The board hangs occasionally on PCI probe after:
>>
>>   phy7: lane number 0, val 1
>>
>> On other boots, it continues to:
>>
>>   rockchip-dw-pcie 3c0800000.pcie@fe280000.of: Phy link never came up
>>
>> In both cases, the hang affects the second PCIe host controller
>> to probe and the first probe never hangs:
>>
>>   rockchip-dw-pcie 3c0000000.pcie@fe260000.of: Phy link never came up
>>
>> This hang happens on the very first read access to the PCI controller
>> at register PCIE_ATU_VIEWPORT. Reading Linux code, the first access
>> seems to be to PCIE_VERSION_NUMBER (0x8F8), but accessing that in
>> barebox equally hangs from time to time.
>>
>> My board doesn't have any PCIe devices connected and this hang
>> doesn't happen in Linux and doesn't happen on the QNAP
>> TS433-eU, which is also RK3568, but actually has PCIe devices, which are
>> probed normally.
>>
>> Disable the device in barebox, so the board is usable with
>> rockchip_v8_defconfig, which enables the PCI driver.
>> barebox,status is used, so the Linux device tree is not affected.
> 
> The barebox internal device-tree is passed to Linux? Else we just can
> make use of the "normal" status field since it would be not propagated
> to Linux as well.

With barebox as EFI loader, we always install the barebox DT in a configuration
table and leaves it to grub or whatever to decide whether it wants to use it or
if it wants to use another DT it finds itself.

The support for the Android fastboot's protocol boot command also doesn't pass
a DT and expects the bootloader to pass its.

Cheers,
Ahmad
> 
> Regards,
>   Marco
> 
>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
>> ---
>>  arch/arm/dts/rk3568-rock-3a.dts | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm/dts/rk3568-rock-3a.dts b/arch/arm/dts/rk3568-rock-3a.dts
>> index bcbfab14a580..b7258d7e61b3 100644
>> --- a/arch/arm/dts/rk3568-rock-3a.dts
>> +++ b/arch/arm/dts/rk3568-rock-3a.dts
>> @@ -55,3 +55,7 @@ environment_sd: partition@408000 {
>>  		};
>>  	};
>>  };
>> +
>> +&pcie3x2 {
>> +	barebox,status = "disabled";
>> +};
>> -- 
>> 2.47.3
>>
>>
>>
> 


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