在 2022/2/14 15:50, Tony Lindgren 写道:
* qianfan <qianfanguijin@xxxxxxx> [220212 02:18]:
在 2022/2/3 17:07, Tony Lindgren 写道:
Hi,
* qianfan <qianfanguijin@xxxxxxx> [220119 08:36]:
Hi everyone:
On my board there has a gpio watchdong connected on am3358. And I found that
the omap gpio device ready too later so it takes about 5 seconds when the
gpio-wdt is ready.
I had tested on some version of linux, check when the OMAP GPIO is ready.
Next is the log:
v4.19 [ 0.195191] OMAP GPIO hardware version 0.1
v5.4 [ 1.168868] OMAP GPIO hardware version 0.1
v5.9 [ 4.598052] OMAP GPIO hardware version 0.1
v5.15 [ 1.253851] OMAP GPIO hardware version 0.1
I can't find which commit slowdown omap gpio driver. could you please give
me some advice?
We've moved to probe pretty much everything at normal module_init time
instead of trying to probe everything early. Only clocks and system timers
need to be probed early for the omap variants.
One of the reasons for the device drivers probing later on during the boot
is caused by drivers/bus/ti-sysc.c. As ti-sysc is the parent device on the
interconnect, none of it's child devices probe before it. And there should
not be any need to probe ti-sysc early. The total boot-up time should be
about the same, just the probe order has changed. If there are issues with
the boot-up time in general, then that's a bug.
Maybe you want to configure the watchdog in the bootloader initially until
the Linux device drivers get probed?
Yes, the gpio watchdog is alived on bootloader, I want find a good way to
feed it until linux driver ready. gpio-wdt.c has an option
CONFIG_GPIO_WATCHDOG_ARCH_INITCALL which will register gpio-wdt driver on
arch_innitcall, but this feature doesn't work on am335x platform due to the
gpio driver ready too later.
Well seems like the boottime of 1.25 seconds to having the gpio probed should
be way longer than your bootloader configured watchdog timeout :) What do you
have the bootloader set the watchdog timeout?
I had sniffer the gpio data by using logic analysis, when the linux
gpio-wdt driver toggle watchdog pin, it passed about 5 seconds after the
u-boot done. And the gpio watchdog's deadline is 1.6s.
Regards,
Tony
