Re: [PATCH] arm64: dts: qcom: glymur: Drop fake PCIe phy 3B

[Konrad Dybcio]

On 6/9/26 12:28 PM, Krzysztof Kozlowski wrote:
> On 24/04/2026 13:09, Konrad Dybcio wrote:
>> On 4/23/26 9:16 AM, Krzysztof Kozlowski wrote:
>>> On 22/04/2026 22:08, Dmitry Baryshkov wrote:
>>>> On Tue, Apr 21, 2026 at 08:41:14AM +0200, Krzysztof Kozlowski wrote:
>>>>> On 20/04/2026 20:02, Dmitry Baryshkov wrote:
>>>>>> On Mon, Apr 20, 2026 at 03:36:17PM +0200, Krzysztof Kozlowski wrote:
>>>>>>> According to user manual / programming guide there is no separate PCIe
>>>>>>> phy 3A and 3B, but one 8-lane QMP PCIe Gen5 PHY which consists of two
>>>>>>> 4-lane blocks.  This is also visible in memory map, where the 0xf00000
>>>>>>> is marked as the main block with additional sub blocks for each 4-lane
>>>>>>> phys.
>>>>>>>
>>>>>>> Describing the sub phys without the rest is not correct from hardware
>>>>>>> description, even if it works.
>>>>>>
>>>>>> Is this the case for the other bifurcated PHYs?
>>>>>>
>>>>>
>>>>> There's more? Oh damn...
>>>>
>>>> In the previous generations. I think Hamoa had one.
>>
>> Any PHY with a name ending in -A or -B. That means:
>>
>> $ rg 'PCIE_.[AB]_' drivers/clk/qcom/ -l
>> drivers/clk/qcom/gcc-x1e80100.c
>> drivers/clk/qcom/gcc-glymur.c
>> drivers/clk/qcom/gcc-sc8280xp.c
>>
>>
>> And, quite predictably, some PHYs may not only bifurcate, but also
>> tri- or quadfurcate (on Nord).
>>
>>> Ah, I did not check the others and there is little we can do there -
>>> it's released DTS. This cannot be easily changed while keeping DTS
>>> compatible with users, because probably two PHY nodes will be replaced
>>> by one with different compatible.
>>
>> I think no one utilized the non-reference configuration of those PHYs
>> in practice. Should a device like that come around though, we'll think
>> about what to do then..
>>
> 
> What is the resolution of this discussion? I have impression that no one
> objected to my patch, so maybe I should resend it?

Qiang is working on a proper solution to this. PCIe3B is nominally used
for a secondary NVMe, so on the occasion that someone has one inserted,
this isn't really a huge loss (the Yoga laptop and the CRD both have
a primary NVMe on PCIe5 IIRC)

Konrad