Re: [PATCH v3 0/5] rtc-at91rm9200: add shadow interrupt mask

From: Nicolas Ferre
Date: Thu May 30 2013 - 04:19:03 EST


On 30/05/2013 01:22, Douglas Gilbert :
On 13-05-29 04:41 PM, Robert Nelson wrote:
On Wed, May 29, 2013 at 3:33 PM, Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
On Thu, 23 May 2013 10:38:50 +0200 Johan Hovold <jhovold@xxxxxxxxx>
wrote:

This is an update of the shadow-interrupt-mask series against
v3.10-rc2.

I guess we need Atmel to confirm that all sam9x5 SoCs are indeed
affected. If not, then some probing mechanism as the one Doug suggested
could be implemented on top of (a subset of) these patches. What do you
say, Nicolas?

Note that the first patch (adding a missing OF compile guard) could be
applied straight away.

At this stage it is unclear to me how to proceed with patches 2-5.

fyi:

A version of these patches had been applied once before:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0ef1594c017521ea89278e80fe3f80dafb17abde


But due to a few issues it was later reverted:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e24b0bfa2f0446ffaad2661040be23668133aef8


Strange life of a patch. Mine was the original, Johan Hovold
objected and had it reverted. Johan then presented his first
patch then v2. They got lost in the weeds.

No, they were not lost. No patch is ever lost and this thread is the proof.

My hardware was still broken and this bug caused collateral
damage. My original patch no longer applied to lk 3.10.0-rc1
so I rewrote it, borrowing some of Johan's ideas and doing a
probe time check for the broken RTC_IMR. That patch was
presented about a week ago:
http://marc.info/?l=linux-arm-kernel&m=136917492531478&w=2
The top of that post gives some more background.

That prompted Johan to produce v3 of his patch which is the
subject of this thread. I was hoping that Nicolas Ferre would
comment or ack one of these patches. Still waiting.

Sure that all this did not progressed at the speed you expected. I understand that. But even if I did not answered in a timely manner, that does not mean that I didn't considered it and marked it as "things to be done before next merge window"...

So, today, too late, I gave my "Acked-by". Sorry for the delay. Let's still monitor the progress of this series upstream.

I have a copy of the original, publicly released manual for
the at91sam9g25 (a member of the at91sam9x5 family) marked
"11032A–ATARM–27-Jul-11". It contains the following:
Errata
49.3.1
RTC: Interrupt Mask Register cannot be used
Interrupt Mask Register reading always returns 0.

Both Rev B and Rev C of that manual drop that particular
erratum. My g25 SoC-based subsystems come from an Atmel
partner and still have the RTC IMR bug.

We already talked about this Douglas. Why are you saying this again. So, to summarize:

1/ each and every at91sam9x5 family SoC have and will probably always have this IMR bug (including 9g25 which is part of the family).

2/ you kindly reported the errata disappearing in the documentation. It is an error with document appearance which you probably noted. I have made the necessary actions to correct this. But here again, you have to be patient waiting for the datasheet's next revision.

Best regards,
--
Nicolas Ferre
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