Re: [PATCH v2 4/4] drivers: misc: Add Support for TMR Inject IP

From: Greg KH
Date: Fri Jul 29 2022 - 05:02:29 EST


On Fri, Jul 29, 2022 at 01:43:47PM +0530, Rao, Appana Durga Kedareswara wrote:
> Hi Greg,
>
> Thanks for the review.
>
> On 28/07/22 7:54 pm, Greg KH wrote:
> > On Wed, Jul 20, 2022 at 11:30:16AM +0530, Appana Durga Kedareswara rao wrote:
> > > From: Appana Durga Kedareswara rao <appana.durga.rao@xxxxxxxxxx>
> > >
> > > The Triple Modular Redundancy(TMR) provides functional fault injection by
> > > changing selected MicroBlaze instructions, which provides the possibility
> > > to verify that the TMR subsystem error detection and fault recovery logic
> > > is working properly, provided sysfs entries which allow the user to inject
> > > a fault.
> >
> > We already have a fault-injection api, why are you not using that?
> >
>
> Inorder to inject the error using TMR inject IP, The API
> which injects the error should be executed from Processor LMB,
> below sysfs entry calls microblaze core API xmb_inject_err()
> which switches the processor to real mode and injects the error,
> Please find the code corresponds to xmb_inject_err() API here:
> https://www.spinics.net/lists/arm-kernel/msg991888.html

You did not answer the question. Why are you not using the in-kernel
fault injection userspace api and why have you created your own?

Also, please use lore.kernel.org links when possible.

thanks,

greg k-h