From: Guenter Roeck <linux@roeck-us.net>
To: Eddie James <eajames@linux.vnet.ibm.com>
Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
joel@jms.id.au, wim@linux-watchdog.org,
Milton Miller <miltonm@us.ibm.com>
Subject: Re: [PATCH 2/2] watchdog: aspeed: Allow configuring for alternate boot
Date: Fri, 16 Mar 2018 15:24:09 -0700 [thread overview]
Message-ID: <20180316222409.GA13278@roeck-us.net> (raw)
In-Reply-To: <bab2d3b4-536c-5dcb-4a13-95a29560d416@linux.vnet.ibm.com>
On Wed, Mar 14, 2018 at 02:53:13PM -0500, Eddie James wrote:
>
>
> On 03/09/2018 04:06 PM, Guenter Roeck wrote:
> >On Fri, Mar 09, 2018 at 03:58:20PM -0600, Eddie James wrote:
> >>From: Milton Miller <miltonm@us.ibm.com>
> >>
> >>Allow the device tree to specify a watchdog to fallover to
> >>the alternate boot source.
> >>
> >>The aspeeed watchdog can set a latch directing flash chip select 0 to
> >>chip select 1, allowing boot from an alternate media if the watchdog
> >>is not reset in time. On the ast2400 bank 1 also goes to flash bank 1,
> >>while on the ast2500 the chip selects are swapped.
> >>
> >>Signed-off-by: Milton Miller <miltonm@us.ibm.com>
> >>Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
> >This is already documented in the bindings document, so the property
> >should be ok.
> >
> >Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>
> Thanks. On a related note, our system has need of a way to determine if it's
> currently booted from the alternate chip or not. It seems the only way to
> tell is to look at the ast2400/2500 watchdog timeout status register. We can
> add some debugfs to the aspeed driver I guess, but I wonder if this is a
> common enough situation that the watchdog core could use some debugfs or
> sysfs for providing that info?
>
If you have the means to determine that the watchdog timed out in the previous
boot, can you just set the WDIOF_CARDRESET status bit ?
Guenter
> Thanks,
> Eddie
>
> >
> >>---
> >> drivers/watchdog/aspeed_wdt.c | 3 +++
> >> 1 file changed, 3 insertions(+)
> >>
> >>diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> >>index d1987d6..f41d246 100644
> >>--- a/drivers/watchdog/aspeed_wdt.c
> >>+++ b/drivers/watchdog/aspeed_wdt.c
> >>@@ -46,6 +46,7 @@ struct aspeed_wdt_config {
> >> #define WDT_RELOAD_VALUE 0x04
> >> #define WDT_RESTART 0x08
> >> #define WDT_CTRL 0x0C
> >>+#define WDT_CTRL_BOOT_SECONDARY BIT(7)
> >> #define WDT_CTRL_RESET_MODE_SOC (0x00 << 5)
> >> #define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5)
> >> #define WDT_CTRL_RESET_MODE_ARM_CPU (0x10 << 5)
> >>@@ -245,6 +246,8 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> >> }
> >> if (of_property_read_bool(np, "aspeed,external-signal"))
> >> wdt->ctrl |= WDT_CTRL_WDT_EXT;
> >>+ if (of_property_read_bool(np, "aspeed,alt-boot"))
> >>+ wdt->ctrl |= WDT_CTRL_BOOT_SECONDARY;
> >> if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) {
> >> /*
> >>--
> >>1.8.3.1
> >>
>
next prev parent reply other threads:[~2018-03-16 22:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-09 21:58 [PATCH 0/2] aspeed: watchdog: fix system reset and read alt-boot option Eddie James
2018-03-09 21:58 ` [PATCH 1/2] watchdog: aspeed: Fix translation of reset mode to ctrl register Eddie James
2018-03-09 22:03 ` Guenter Roeck
2018-03-09 21:58 ` [PATCH 2/2] watchdog: aspeed: Allow configuring for alternate boot Eddie James
2018-03-09 22:06 ` Guenter Roeck
2018-03-14 19:53 ` Eddie James
2018-03-16 22:24 ` Guenter Roeck [this message]
2018-03-13 4:29 ` Joel Stanley
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