From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-path: Received: from mail-pl0-f67.google.com ([209.85.160.67]:38179 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437AbeCPWYM (ORCPT ); Fri, 16 Mar 2018 18:24:12 -0400 Date: Fri, 16 Mar 2018 15:24:09 -0700 From: Guenter Roeck To: Eddie James Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, joel@jms.id.au, wim@linux-watchdog.org, Milton Miller Subject: Re: [PATCH 2/2] watchdog: aspeed: Allow configuring for alternate boot Message-ID: <20180316222409.GA13278@roeck-us.net> References: <1520632700-25800-1-git-send-email-eajames@linux.vnet.ibm.com> <1520632700-25800-3-git-send-email-eajames@linux.vnet.ibm.com> <20180309220610.GB32606@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org 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 > >> > >>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 > >>Signed-off-by: Eddie James > >This is already documented in the bindings document, so the property > >should be ok. > > > >Reviewed-by: Guenter Roeck > > 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 > >> >