Re: [PATCH 0/2] Add iProc IDM device support

From: Marc Zyngier
Date: Mon Dec 09 2019 - 13:36:43 EST


On Mon, 9 Dec 2019 10:02:53 -0800
Ray Jui <ray.jui@xxxxxxxxxxxx> wrote:

> On 12/7/19 9:39 AM, Marc Zyngier wrote:
> > On Mon, 2 Dec 2019 15:31:25 -0800
> > Ray Jui <ray.jui@xxxxxxxxxxxx> wrote:
> >
> >> The Broadcom iProc IDM device allows control and monitoring of ASIC internal
> >> bus transactions. Most importantly, it can be configured to detect bus
> >> transaction timeout. In such case, critical information such as transaction
> >> address that caused the error, bus master ID of the transaction that caused
> >> the error, and etc., are made available from the IDM device.
> >
> > This seems to have many of the features of an EDAC device reporting
> > uncorrectable errors.
> >
> > Is there any reason why it is not implemented as such?
> >
> > Thanks,
> >
> > M.
> >
>
> I thought EDAC errors (in fact, in our case, that's fatal rather than
> uncorrectable) are mostly for DDR. Is my understanding incorrect?

No, they are for HW errors in general. There is no real limitation of
scope, as far as I understand. Recently, the Annapurna guys came up
with a similar HW block, and were convinced to make it an EDAC device.

See [1] for details.

Thanks,

M.

[1] https://lore.kernel.org/linux-devicetree/1570707681-865-1-git-send-email-talel@xxxxxxxxxx/
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