[PATCH v3 0/6] Improved sysreset/watchdog uclass integration

Fri Nov 5 15:21:20 CET 2021

On Fri, Nov 05, 2021 at 12:14:47PM +0100, Stefan Roese wrote:
> Hi Andre,
> 
> Added Tom to Cc.
> 
> On 05.11.21 11:04, Andre Przywara wrote:
> > On Thu, 4 Nov 2021 20:02:41 -0600
> > Simon Glass <sjg at chromium.org> wrote:
> > 
> > Hi,
> > 
> > > On Thu, 4 Nov 2021 at 19:22, Stefan Roese <sr at denx.de> wrote:
> > > > 
> > > > Hi Andre,
> > > > 
> > > > On 05.11.21 00:11, Andre Przywara wrote:
> > > > > On Thu, 4 Nov 2021 11:37:57 +0100
> > > > > Stefan Roese <sr at denx.de> wrote:
> > > > > 
> > > > > Hi Stefan,
> > > > > > On 04.11.21 04:55, Samuel Holland wrote:
> > > > > > > This series hooks up the watchdog uclass to automatically register
> > > > > > > watchdog devices for use with sysreset, doing a bit of minor cleanup
> > > > > > > along the way.
> > > > > > > 
> > > > > > > The goal is for this to replace the sunxi board-level non-DM reset_cpu()
> > > > > > > function. I was surprised to find that the wdt_reboot driver requires
> > > > > > > its own undocumented device tree node, which references the watchdog
> > > > > > > device by phandle. This is problematic for us, because sunxi-u-boot.dtsi
> > > > > > > file covers 20 different SoCs with varying watchdog node phandle names.
> > > > > > > So it would have required adding a -u-boot.dtsi file for each board.
> > > > > > > 
> > > > > > > Hooking things up automatically makes sense to me; this is what Linux
> > > > > > > does. However, I put the code behind a new option to avoid surprises for
> > > > > > > other platforms.
> > > > > > > 
> > > > > > > Changes in v3:
> > > > > > >     - Move condition to wdt-uclass.c to fix build errors.
> > > > > > >     - Include watchdog name in error message.
> > > > > > > 
> > > > > > > Changes in v2:
> > > > > > >     - Extend the "if SYSRESET" block to the end of the file.
> > > > > > >     - Also make gpio_reboot_probe function static.
> > > > > > >     - Rebase on top of 492ee6b8d0e7 (now handle all watchdogs).
> > > > > > >     - Added patches 5-6 as an example of how the new option will be used.
> > > > > > > 
> > > > > > > Samuel Holland (6):
> > > > > > >      sysreset: Add uclass Kconfig dependency to drivers
> > > > > > >      sysreset: Mark driver probe functions as static
> > > > > > >      sysreset: watchdog: Move watchdog reference to plat data
> > > > > > >      watchdog: Automatically register device with sysreset
> > > > > > >      sunxi: Avoid duplicate reset_cpu with SYSRESET enabled
> > > > > > >      sunxi: Use sysreset framework for poweroff/reset
> > > > > > > 
> > > > > > >     arch/arm/Kconfig                     |  3 +++
> > > > > > >     arch/arm/mach-sunxi/board.c          |  2 ++
> > > > > > >     drivers/sysreset/Kconfig             | 11 ++++++--
> > > > > > >     drivers/sysreset/sysreset_gpio.c     |  2 +-
> > > > > > >     drivers/sysreset/sysreset_resetctl.c |  2 +-
> > > > > > >     drivers/sysreset/sysreset_syscon.c   |  2 +-
> > > > > > >     drivers/sysreset/sysreset_watchdog.c | 40 ++++++++++++++++++++++------
> > > > > > >     drivers/watchdog/wdt-uclass.c        |  8 ++++++
> > > > > > >     include/sysreset.h                   | 10 +++++++
> > > > > > >     9 files changed, 67 insertions(+), 13 deletions(-)
> > > > > > 
> > > > > > Applied to u-boot-marvell
> > > > > 
> > > > > Mmmh, why u-boot-marvell,
> > > > 
> > > > Because I'm handling watchdog related changed since a few years and we
> > > > did not create a specific subsystem repo for this and I'm usually
> > > > using my "marvell" one for this.

And fwiw, there's a few other cases like this.  If it's too confusing,
maybe we should just roll out a few more repositories, I think it's
easier to do that now than pre-gitlab?

> > > > > and why did this end up already in master?
> > > > > Isn't that material for the next merge window? After all this changes
> > > > > quite a bit, for a lot of boards, and I did not have a closer look at
> > > > > the sunxi parts yet.
> > > > 
> > > > I was hesitating also a bit. But since this patchset is on the list in
> > > > v1 since over 2 months now (2021-08-21) I thought it was "ready" for
> > > > inclusion now. We are at -rc1 and I think we still have enough time to
> > > > fix any resulting problems in this release cycle.
> > 
> > Why do we have the merge window then? This is clearly not a regression or
> > general fix.
> 
> AFAIU, we are a bit less strict here in U-Boot. Patches that were posted
> before the merge-window and skipped the review process (most likely
> because of lack of time) are often still integrated in the early rcX
> cycles. At least this is how I handle it usually.
> 
> Tom, is my understanding here correct?

Yes.  We are not as strict as the kernel is about what can come in
between rc1 and rc2 (and to a certain degree, post rc2).  I leave things
up to the discretion of the custodians.  People tend of have less time
to handle U-Boot changes than other stuff, so I try and be flexible in
picking things up.

> > > Yes I agree, that should be plenty of time for people to review it.
> > 
> > Well, if there would be people to review the sunxi parts :-(
> > I am totally fine with the generic patches (as they have been reviewed),
> > but the sunxi integration is somewhat risky.
> > I was explicitly deprioritising that in my queue, as it really doesn't
> > change, add or fix anything, it's mere refactoring, from the user's point
> > of view.
> > 
> > > > Do you see any specific issues?
> > 
> > Patch 6/6 changes the config for all 157 Allwinner boards, so I think that
> > deserves at least some testing, *before* merging it.
> 
> I expect that Samuel did some testing. But still, I agree that it
> would be much better, if these patches - especially the Allwinner parts
> got more extensive testing.
> 
> > I will do as much testing now as possible, but I am not happy about that
> > situation.
> 
> Understood. Should we revert patch 6/6 for now?

FWIW, given Samuel has been doing a number of allwinner changes, I had
also assumed it was sufficiently tested, which is why I didn't raise a
further concern when I saw the widespread nature of the overall changes,
just figured it was a few more ready-to-go cleanups that weren't quite
picked up in time.  Please do speak up if you want me to revert the last
part.

-- 
Tom
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