mbox series

[v3,0/3] Add support for WDIOF_CARDRESET on TI AM65x

Message ID 20230713095127.1230109-1-huaqian.li@siemens.com (mailing list archive)
Headers show
Series Add support for WDIOF_CARDRESET on TI AM65x | expand

Message

Li, Hua Qian July 13, 2023, 9:51 a.m. UTC
From: Li Hua Qian <huaqian.li@siemens.com>

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/20230711091713.1113010-1-huaqian.li@siemens.com

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/3137d87e56ef75ba0b8a923d407b2fecace6ccbd.camel@siemens.com/
  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(+)

Comments

Guenter Roeck July 13, 2023, 5:21 p.m. UTC | #1
On 7/13/23 02:51, huaqian.li@siemens.com wrote:
> From: Li Hua Qian <huaqian.li@siemens.com>
> 
> 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/20230711091713.1113010-1-huaqian.li@siemens.com
> 
> 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/3137d87e56ef75ba0b8a923d407b2fecace6ccbd.camel@siemens.com/
>    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(+)
>
Li, Hua Qian July 14, 2023, 7 a.m. UTC | #2
On Thu, 2023-07-13 at 10:21 -0700, Guenter Roeck wrote:
> On 7/13/23 02:51, huaqian.li@siemens.com wrote:
> > From: Li Hua Qian <huaqian.li@siemens.com>
> > 
> > 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/20230711091713.1113010-1-huaqian.li@siemens.com
> > 
> > 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/3137d87e56ef75ba0b8a923d407b2fecace6ccbd.camel@siemens.com/
> >    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(+)
> > 
>