Hi Chris,
On mer., janv. 10 2018, Chris Packham <Chris.Packham@xxxxxxxxxxxxxxxxxxx> wrote:
> On 10/01/18 21:31, Gregory CLEMENT wrote:
>> Hi Chris,
>>
>> On mar., janv. 09 2018, Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>>> The Armada-38x uses an SDRAM controller that is compatible with the
>>> Armada-XP. The key difference is the width of the bus (XP is 64/32, 38x
>>> is 32/16). The SDRAM controller registers are the same between the two
>>> SoCs.
>>>
>>> Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
>>> ---
>>> arch/arm/boot/dts/armada-38x.dtsi | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi
>>> index 00ff549d4e39..6d34c5ec178f 100644
>>> --- a/arch/arm/boot/dts/armada-38x.dtsi
>>> +++ b/arch/arm/boot/dts/armada-38x.dtsi
>>> @@ -138,6 +138,11 @@
>>> #size-cells = <1>;
>>> ranges = <0 MBUS_ID(0xf0, 0x01) 0 0x100000>;
>>>
>>> + sdramc@1400 {
>>
>> Could you add a label? Thanks to this it would be possible to
>> enable/disable it at board level in a esay way.
>>
>
> Sure. Any suggestions for a name better than "sdramc:"?
For me sdramc: is fine.
>
> It's probably worth adding the same label to armada-xp.dtsi and
> armada-xp-98dx3236.dtsi.
Right.
>
>>> + compatible = "marvell,armada-xp-sdram-controller";
>>> + reg = <0x1400 0x500>;
>>
>> What about adding status = "disabled" ?
>>
>> Thanks to this we can enable it at board level only if we really want
>> it, it would avoid nasty regression on boards that don't need it, if an
>> issue occurs. Unless you are sure that it is completely safe to enable
>> it for everyone.
>
> The EDAC driver (which is default n) will not probe the device if ECC
> has not been enabled so that should be safe.
OK in this case no need to disable it by default.
Thanks,
Gregory
>
> Other than the EDAC driver the only other code that looks at this is in
> arch/arm/mach-mvebu/pm.c and it almost seems like an omission that this
> code is not active on armada-38x. The armada-38x platforms I have access
> to don't use suspend/resume so I can't verify this.
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
