On Thu, Jan 07, 2021 at 08:37:03AM +0200, Matti Vaittinen wrote:
> If config for BD70528 watchdog is enabled when BD71828 or BD71815
> are used the RTC module will issue call to BD70528 watchdog with
> NULL data. Ignore this call and don't crash.
>
> Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
I really think this should be handled in the calling code.
Also, I am curious how this is supposed to work.
The code is called with
ret = bd70528_wdt_set(r->parent, new_state & BD70528_WDT_STATE_BIT,
old_state);
from bd70528_set_rtc_based_timers(). That same function subsequently
calls bd70528_set_elapsed_tmr() with the same parameter, and that
parameter is dereferenced in bd70528_set_elapsed_tmr() without checking.
Conceptually, it should not be necessary to determine at compile-time
which of the chips is in the system. It should be posible to compile
a single kernel which supports all chips.
Guenter
> ---
> drivers/watchdog/bd70528_wdt.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/watchdog/bd70528_wdt.c b/drivers/watchdog/bd70528_wdt.c
> index 0170b37e6674..fde242b8a4a6 100644
> --- a/drivers/watchdog/bd70528_wdt.c
> +++ b/drivers/watchdog/bd70528_wdt.c
> @@ -49,6 +49,21 @@ int bd70528_wdt_set(struct rohm_regmap_dev *data, int enable, int *old_state)
> u8 wd_ctrl_arr[3] = { WD_CTRL_MAGIC1, WD_CTRL_MAGIC2, 0 };
> u8 *wd_ctrl = &wd_ctrl_arr[2];
>
> + /*
> + * BD71828 and BD71815 use same RTC driver as BD70528.
> + * BD71815 and BD71828 do not need MFD data as they do not share
> + * RTC counter with watchdog. The BD70528 watchdog should not be
> + * compiled in with BD71815 or BD71828 and the stub implementation
> + * for the bd70528_wdt_set should be provided instead.
> + *
> + * If one compiles this watchdog with BD71828 or BD71815 - the call
> + * from RTC may get here and the data pointer is NULL. In that case,
> + * warn and go out.
> + */
> + if (!data) {
> + pr_warn("BD70528_WATCHDOG misconfigured\n");
> + return 0;
> + }
> ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp);
> if (ret)
> return ret;
>
> base-commit: 2c85ebc57b3e1817b6ce1a6b703928e113a90442
> --
> 2.25.4
>
>
> --
> Matti Vaittinen, Linux device drivers
> ROHM Semiconductors, Finland SWDC
> Kiviharjunlenkki 1E
> 90220 OULU
> FINLAND
>
> ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
> Simon says - in Latin please.
> ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
> Thanks to Simon Glass for the translation =]
