Re: [PATCH v3 0/3] Add support for RAS DES feature in PCIe DW

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Tue, 25 Jun 2024 15:08:10 +0530
Shradha Todi <shradha.t@samsung.com> wrote:

> 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.

To consider this properly I think some documentation is needed.

Maybe just ABI in Documentation/ABI/testing/debugfs-*
or maybe a more freestanding document.


> 
> v2: https://lore.kernel.org/lkml/20240319163315.GD3297@thinkpad/T/
> 
> v1: https://lore.kernel.org/all/20210518174618.42089-1-shradha.t@samsung.com/T/
> 
> Shradha Todi (3):
>   PCI: dwc: Add support for vendor specific capability search
>   PCI: debugfs: Add support for RASDES framework in DWC
>   PCI: dwc: Create debugfs files in DWC driver
> 
>  drivers/pci/controller/dwc/Kconfig            |   8 +
>  drivers/pci/controller/dwc/Makefile           |   1 +
>  .../controller/dwc/pcie-designware-debugfs.c  | 474 ++++++++++++++++++
>  .../controller/dwc/pcie-designware-debugfs.h  |   0
>  .../pci/controller/dwc/pcie-designware-host.c |   2 +
>  drivers/pci/controller/dwc/pcie-designware.c  |  20 +
>  drivers/pci/controller/dwc/pcie-designware.h  |  18 +
>  7 files changed, 523 insertions(+)
>  create mode 100644 drivers/pci/controller/dwc/pcie-designware-debugfs.c
>  create mode 100644 drivers/pci/controller/dwc/pcie-designware-debugfs.h
>