> -----Original Message----- > From: Shradha Todi <shradha.t@xxxxxxxxxxx> > Sent: 04 December 2023 14:10 > To: 'Manivannan Sadhasivam' <manivannan.sadhasivam@xxxxxxxxxx> > Cc: 'lpieralisi@xxxxxxxxxx' <lpieralisi@xxxxxxxxxx>; 'kw@xxxxxxxxx' > <kw@xxxxxxxxx>; 'robh@xxxxxxxxxx' <robh@xxxxxxxxxx>; > 'bhelgaas@xxxxxxxxxx' <bhelgaas@xxxxxxxxxx>; 'jingoohan1@xxxxxxxxx' > <jingoohan1@xxxxxxxxx>; 'gustavo.pimentel@xxxxxxxxxxxx' > <gustavo.pimentel@xxxxxxxxxxxx>; 'josh@xxxxxxxxxxxxxxxx' > <josh@xxxxxxxxxxxxxxxx>; 'lukas.bulwahn@xxxxxxxxx' > <lukas.bulwahn@xxxxxxxxx>; 'hongxing.zhu@xxxxxxx' > <hongxing.zhu@xxxxxxx>; 'pankaj.dubey@xxxxxxxxxxx' > <pankaj.dubey@xxxxxxxxxxx>; 'linux-kernel@xxxxxxxxxxxxxxx' <linux- > kernel@xxxxxxxxxxxxxxx>; 'linux-pci@xxxxxxxxxxxxxxx' <linux- > pci@xxxxxxxxxxxxxxx> > Subject: RE: [PATCH v2 0/3] Add support for RAS DES feature in PCIe DW > controller > > > > > -----Original Message----- > > From: Manivannan Sadhasivam [mailto:manivannan.sadhasivam@xxxxxxxxxx] > > Sent: 30 November 2023 22:25 > > To: Shradha Todi <shradha.t@xxxxxxxxxxx> > > Cc: lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; robh@xxxxxxxxxx; > > bhelgaas@xxxxxxxxxx; jingoohan1@xxxxxxxxx; > > gustavo.pimentel@xxxxxxxxxxxx; josh@xxxxxxxxxxxxxxxx; > > lukas.bulwahn@xxxxxxxxx; hongxing.zhu@xxxxxxx; > > pankaj.dubey@xxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > > pci@xxxxxxxxxxxxxxx > > Subject: Re: [PATCH v2 0/3] Add support for RAS DES feature in PCIe DW > > controller > > > > On Thu, Nov 30, 2023 at 05:20:41PM +0530, Shradha Todi 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. > > > > > > v1 version was posted long back and for some reasons I couldn't work > > > on it. I apologize for the long break. I'm restarting this activity > > > and have taken care of all previous review comments shared. > > > v1: > > > https://lore.kernel.org/all/20210518174618.42089-1-shradha.t@samsung > > > .c > > > om/T/ > > > > > > > There is already a series floating to add similar functionality via > > perf > > subsystem: https://lore.kernel.org/linux-pci/20231121013400.18367-1- > > xueshuai@xxxxxxxxxxxxxxxxx/ > > > > - Mani > > > > Hi Mani, > > The series proposed in perf includes only time based-analysis and event counters > which will monitor performance (Group 6 and 7). The patch or framework that we > have proposed includes debug information, error injection facility and error > counters (Group 0 - 5) which are not included as part of the functionality > implemented via perf. In my opinion, these functionalities don't count as > performance monitoring or counters but rather as debug counters. How about > we take this up as a debugfs framework as proposed in my patch? > Or if others feel it can be taken via perf driver then I am happy to extend the perf > driver if authors do not have objection. Let me know what you think of this? > Meanwhile I will review the perf patches and share my feedback. > Hello Mani, Any update on the above comment? IMO, even though the perf patches and this patchset are both part of the DWC vendor specific capability - RASDES, they cover different features. The perf file includes performance based parameters like time-based analysis and event counters for count of packets whereas this patchset includes debugging fields, error injection and event counters for count of errors. I think having a separate debugfs file fits more but would you suggest we extend the perf file itself? Shradha > > > 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 | 476 > > ++++++++++++++++++ > > > .../controller/dwc/pcie-designware-debugfs.h | 0 > > > drivers/pci/controller/dwc/pcie-designware.c | 20 + > > > drivers/pci/controller/dwc/pcie-designware.h | 18 + > > > 6 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 > > > > > > -- > > > 2.17.1 > > > > > > > -- > > மணிவண்ணன் சதாசிவம்
