Hi Guenter,
On 11 June 2015 at 13:49, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> On 06/10/2015 10:44 PM, Fu Wei wrote:
>>
>> Hi Guenter,
>>
>> On 11 June 2015 at 13:33, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>>>
>>> On 06/10/2015 10:47 AM, fu.wei@xxxxxxxxxx wrote:
>>>>
>>>>
>>>> From: Fu Wei <fu.wei@xxxxxxxxxx>
>>>>
>>>> This driver bases on linux kernel watchdog framework.
>>>> It supports getting timeout from parameter and FDT
>>>> at the driver init stage.
>>>> The first timeout period expires, the interrupt routine
>>>> got another timeout period to run panic for saving
>>>> system context.
>>>>
>>>> Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
>>>> ---
>>>> drivers/watchdog/Kconfig | 11 ++
>>>> drivers/watchdog/Makefile | 1 +
>>>> drivers/watchdog/sbsa_gwdt.c | 383
>>>> +++++++++++++++++++++++++++++++++++++++++++
>>>> 3 files changed, 395 insertions(+)
>>>> create mode 100644 drivers/watchdog/sbsa_gwdt.c
>>>>
>>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>>>> index e5e7c55..554f18a 100644
>>>> --- a/drivers/watchdog/Kconfig
>>>> +++ b/drivers/watchdog/Kconfig
>>>> @@ -152,6 +152,17 @@ config ARM_SP805_WATCHDOG
>>>> ARM Primecell SP805 Watchdog timer. This will reboot your
>>>> system
>>>> when
>>>> the timeout is reached.
>>>>
>>>> +config ARM_SBSA_WATCHDOG
>>>> + tristate "ARM SBSA Generic Watchdog"
>>>> + depends on ARM64
>>>> + depends on ARM_ARCH_TIMER
>>>> + select WATCHDOG_CORE
>>>> + help
>>>> + ARM SBSA Generic Watchdog. This watchdog has two Watchdog
>>>> timeouts.
>>>> + The first timeout will trigger a panic; the second timeout
>>>> will
>>>> + trigger a system reset.
>>>> + More details: ARM DEN0029B - Server Base System Architecture
>>>> (SBSA)
>>>> +
>>>> config AT91RM9200_WATCHDOG
>>>> tristate "AT91RM9200 watchdog"
>>>> depends on SOC_AT91RM9200 && MFD_SYSCON
>>>> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
>>>> index 5c19294..471f1b7c 100644
>>>> --- a/drivers/watchdog/Makefile
>>>> +++ b/drivers/watchdog/Makefile
>>>> @@ -30,6 +30,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
>>>>
>>>> # ARM Architecture
>>>> obj-$(CONFIG_ARM_SP805_WATCHDOG) += sp805_wdt.o
>>>> +obj-$(CONFIG_ARM_SBSA_WATCHDOG) += sbsa_gwdt.o
>>>> obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
>>>> obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
>>>> obj-$(CONFIG_CADENCE_WATCHDOG) += cadence_wdt.o
>>>> diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
>>>> new file mode 100644
>>>> index 0000000..1ddc10f
>>>> --- /dev/null
>>>> +++ b/drivers/watchdog/sbsa_gwdt.c
>>>> @@ -0,0 +1,383 @@
>>>> +/*
>>>> + * SBSA(Server Base System Architecture) Generic Watchdog driver
>>>> + *
>>>> + * Copyright (c) 2015, Linaro Ltd.
>>>> + * Author: Fu Wei <fu.wei@xxxxxxxxxx>
>>>> + * Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or modify
>>>> + * it under the terms of the GNU General Public License 2 as published
>>>> + * by the Free Software Foundation.
>>>> + *
>>>> + * This program is distributed in the hope that it will be useful,
>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>>> + * GNU General Public License for more details.
>>>> + *
>>>> + * Note: This SBSA Generic watchdog has two stage timeouts,
>>>> + * When the first timeout occurs, WS0(SPI or LPI) is triggered,
>>>> + * the second timeout period(as long as the first timeout period)
>>>> starts.
>>>> + * In WS0 interrupt routine, panic() will be called for
>>>> collecting
>>>> + * crashdown info.
>>>> + * If system can not recover from WS0 interrupt routine, then
>>>> second
>>>> + * timeout occurs, WS1(reset or higher level interrupt) is
>>>> triggered.
>>>> + * The two timeout period can be set by WOR(32bit).
>>>> + * WOR gives a maximum watch period of around 10s at the maximum
>>>> + * system counter frequency.
>>>> + * The System Counter shall run at maximum of 400MHz.
>>>> + *
>>>> + * But If we need a larger timeout period, this driver will
>>>> programme WCV
>>>> + * directly. That can support more than 10s timeout at the
>>>> maximum
>>>> + * system counter frequency.
>>>> + * More details: ARM DEN0029B - Server Base System Architecture
>>>> (SBSA)
>>>> + *
>>>> + * SBSA GWDT: |---WOR(or WCV)---WS0---WOR(or WCV)---WS1
>>>> + * |-----timeout-----WS0-----timeout-----WS1
>>>
>>>
>>>
>>> If we use WCV at all, I would like to see something like
>>>
>>> * SBSA GWDT: |---WOR(or WCV)---WS0--------WOR------WS1
>>> * |-----timeout-----WS0-----------------WS1
>>> * panic hw reset
>>>
>>> where WOR would be used up to its maximum, to be replaced by WCV
>>> (but kept at maximum) if the selected timeout is larger than the
>>> maximum timeout selectable with WOR. Would this be possible ?
>>
>>
>> for this part |-----timeout-----WS0, I am doing this way in
>> non-pretimeout version.
>>
>> but for WS0-----------------WS1, do you mean WOR would always be used
>> up to its maximum???
>
>
> yes
>
>> I don't see any variable attached on it. So I would like to confirm
>> what is this value
>>
>
> min(timeout, max_wor_timeout)
Sure, no problem. just need a very little fix in non-pretimout version
Just delete several lines in "sbsa_gwdt_interrupt", become like this:
+static irqreturn_t sbsa_gwdt_interrupt(int irq, void *dev_id)
+{
+ panic("SBSA Watchdog pre-timeout");
+
+ return IRQ_HANDLED;
+}
this matches your thought.
Any other code I need to improve ? If It is OK for you, I can sent a
new patchset soon.
Please let me know anything else I need to improve.
Great thanks for your time
>
> Guenter
>
--
Best regards,
Fu Wei
Software Engineer
Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch
Ph: +86 21 61221326(direct)
Ph: +86 186 2020 4684 (mobile)
Room 1512, Regus One Corporate Avenue,Level 15,
One Corporate Avenue,222 Hubin Road,Huangpu District,
Shanghai,China 200021
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