On Thu, 2023-07-13 at 10:21 -0700, Guenter Roeck wrote: > On 7/13/23 02:51, huaqian.li@xxxxxxxxxxx wrote: > > From: Li Hua Qian <huaqian.li@xxxxxxxxxxx> > > > > 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@xxxxxxxxxxx > > > > 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@xxxxxxxxxxx/ > > 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(+) > > >
