Re: [PATCH v2 0/2] usb: typec: Add new driver for Parade PS8830 Type-C Retimer

[Konrad Dybcio <konradybcio@gmail.com>]

On 10/15/24 15:03, Abel Vesa wrote:
> On 24-10-15 14:41:25, Johan Hovold wrote:
>> On Fri, Oct 04, 2024 at 04:57:36PM +0300, Abel Vesa wrote:
>>> The Parade PS8830 is a Type-C multi-protocol retimer that is controlled
>>> via I2C. It provides altmode and orientation handling and usually sits
>>> between the Type-C port and the PHY.
>>>
>>> It is currently used alongside Qualcomm Snapdragon X Elite SoCs on quite
>>> a few laptops already.
>>>
>>> This new driver adds support for the following 3 modes:
>>>   - DP 4lanes (pin assignments C and E)
>>>   - DP 2lanes + USB3 (pin assignment D)
>>>   - USB3
>>>
>>> This retimer is a LTTPR (Link-Training Tunable PHY Repeater) which means
>>> it can support link training from source to itself. This means that the
>>> DP driver needs to be aware of the repeater presence and to handle
>>> the link training accordingly. This is currently missing from msm dp
>>> driver, but there is already effort going on to add it. Once done,
>>> full external DP will be working on all X1E laptops that make use of
>>> this retimer.
>>
>> I was gonna ask you to include the devicetree changes that enables the
>> retimers as part of this series (to facilitate review and testing), but
>> perhaps you should indeed not post them again until LTTPR support is in
>> place.
> 
> I was thinking maybe we should not wait for LTTPR support as this series
> brings orientation support as is.

It also happens to bring an undesired crash-on-unplug feature when
DP is enabled.. I suppose it's fine to bring this series in if you
separate enabling the retimer on devices from wiring DP up.

Konrad