2023-07-13 10:10:32

by Li, Hua Qian

[permalink] [raw]
Subject: [PATCH v3 0/3] Add support for WDIOF_CARDRESET on TI AM65x

From: Li Hua Qian <[email protected]>

The watchdog hardware of TI AM65X platform does not support
WDIOF_CARDRESET feature, add a reserved memory to save the watchdog
reset cause, to know if the board reboot is due to a watchdog reset.

Changes in v3:
- Add memory-region back for the reserved memory, and remove reserved
memory from the watchdog IO address space.
- Add changelog.
- Link to v2:
https://lore.kernel.org/linux-watchdog/[email protected]

Changes in v2:
- Remove memory-region and memory-size properties, and bind the reserved
memory to watchdog IO address space.
- Remove the unnecessary rti_wdt_ioctl.
- Fix the mail list
- Link to v1:
https://lore.kernel.org/all/[email protected]/
v1 had a wrong mail list at the beginning, and the mail thread was
messed up.

Li Hua Qian (3):
dt-bindings: watchdog: ti,rti-wdt: Add support for WDIOF_CARDRESET
arm64: dts: ti: Add reserved memory for watchdog
watchdog:rit_wdt: Add support for WDIOF_CARDRESET

.../bindings/watchdog/ti,rti-wdt.yaml | 12 +++++
.../boot/dts/ti/k3-am65-iot2050-common.dtsi | 10 ++++
drivers/watchdog/rti_wdt.c | 51 +++++++++++++++++++
3 files changed, 73 insertions(+)

--
2.34.1



2023-07-13 17:35:39

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v3 0/3] Add support for WDIOF_CARDRESET on TI AM65x

On 7/13/23 02:51, [email protected] wrote:
> From: Li Hua Qian <[email protected]>
>
> The watchdog hardware of TI AM65X platform does not support
> WDIOF_CARDRESET feature, add a reserved memory to save the watchdog
> reset cause, to know if the board reboot is due to a watchdog reset.
>

One thing I keep wondering about: What prevents the Linux kernel from
treating the special memory area like normal memory ? I would have expected
some usage note, such as that the memory area must be reported as reserved
to the kernel, but I don't see anything like that.

Guenter

> Changes in v3:
> - Add memory-region back for the reserved memory, and remove reserved
> memory from the watchdog IO address space.
> - Add changelog.
> - Link to v2:
> https://lore.kernel.org/linux-watchdog/[email protected]
>
> Changes in v2:
> - Remove memory-region and memory-size properties, and bind the reserved
> memory to watchdog IO address space.
> - Remove the unnecessary rti_wdt_ioctl.
> - Fix the mail list
> - Link to v1:
> https://lore.kernel.org/all/[email protected]/
> v1 had a wrong mail list at the beginning, and the mail thread was
> messed up.
>
> Li Hua Qian (3):
> dt-bindings: watchdog: ti,rti-wdt: Add support for WDIOF_CARDRESET
> arm64: dts: ti: Add reserved memory for watchdog
> watchdog:rit_wdt: Add support for WDIOF_CARDRESET
>
> .../bindings/watchdog/ti,rti-wdt.yaml | 12 +++++
> .../boot/dts/ti/k3-am65-iot2050-common.dtsi | 10 ++++
> drivers/watchdog/rti_wdt.c | 51 +++++++++++++++++++
> 3 files changed, 73 insertions(+)
>


2023-07-14 07:52:55

by Li, Hua Qian

[permalink] [raw]
Subject: Re: [PATCH v3 0/3] Add support for WDIOF_CARDRESET on TI AM65x

On Thu, 2023-07-13 at 10:21 -0700, Guenter Roeck wrote:
> On 7/13/23 02:51, [email protected] wrote:
> > From: Li Hua Qian <[email protected]>
> >
> > The watchdog hardware of TI AM65X platform does not support
> > WDIOF_CARDRESET feature, add a reserved memory to save the watchdog
> > reset cause, to know if the board reboot is due to a watchdog
> > reset.
> >
>
> One thing I keep wondering about: What prevents the Linux kernel from
> treating the special memory area like normal memory ? I would have
> expected
> some usage note, such as that the memory area must be reported as
> reserved
> to the kernel, but I don't see anything like that.
>
> Guenter

Could you help to suggest how to handle it?

I am not sure where is a good place to write the usage note. I am
thinking to add it in v4 to DT binding.

Best regards,
Li Hua Qian
>
> > Changes in v3:
> > - Add memory-region back for the reserved memory, and remove
> > reserved
> >    memory from the watchdog IO address space.
> > - Add changelog.
> > - Link to v2:
> >   
> > https://lore.kernel.org/linux-watchdog/[email protected]
> >
> > Changes in v2:
> > - Remove memory-region and memory-size properties, and bind the
> > reserved
> >    memory to watchdog IO address space.
> > - Remove the unnecessary rti_wdt_ioctl.
> > - Fix the mail list
> > - Link to v1:
> >   
> > https://lore.kernel.org/all/[email protected]/
> >    v1 had a wrong mail list at the beginning, and the mail thread
> > was
> >    messed up.
> >
> > Li Hua Qian (3):
> >    dt-bindings: watchdog: ti,rti-wdt: Add support for
> > WDIOF_CARDRESET
> >    arm64: dts: ti: Add reserved memory for watchdog
> >    watchdog:rit_wdt: Add support for WDIOF_CARDRESET
> >
> >   .../bindings/watchdog/ti,rti-wdt.yaml         | 12 +++++
> >   .../boot/dts/ti/k3-am65-iot2050-common.dtsi   | 10 ++++
> >   drivers/watchdog/rti_wdt.c                    | 51
> > +++++++++++++++++++
> >   3 files changed, 73 insertions(+)
> >
>