Re: [PATCH v7 0/5] Add support for debugfs based RAS DES feature in PCIe DW

Krzysztof Wilczyński
2025-02-25T14:30:05Z

Hello,

> DesignWare controller provides a vendor specific extended capability
> called RASDES as an IP feature. This extended capability provides
> hardware information like:
> - Debug registers to know the state of the link or controller.
> - Error injection mechanisms to inject various PCIe errors including
> sequence number, CRC
> - Statistical counters to know how many times a particular event
> occurred
>
> However, in Linux we do not have any generic or custom support to be
> able to use this feature in an efficient manner. This is the reason we
> are proposing this framework. Debug and bring up time of high-speed IPs
> are highly dependent on costlier hardware analyzers and this solution
> will in some ways help to reduce the HW analyzer usage.
>
> The debugfs entries can be used to get information about underlying
> hardware and can be shared with user space. Separate debugfs entries has
> been created to cater to all the DES hooks provided by the controller.
> The debugfs entries interacts with the RASDES registers in the required
> sequence and provides the meaningful data to the user. This eases the
> effort to understand and use the register information for debugging.
>
> This series creates a generic debugfs framework for DesignWare PCIe
> controllers where other debug features apart from RASDES can also be
> added as and when required.

Applied to controller/dwc, thank you!

Krzysztof