From: Simon Arlott Subject: Re: [PATCH 4/4] MIPS: bmips: Convert bcm63xx_wdt to use WATCHDOG_CORE Date: Sat, 21 Nov 2015 21:44:27 +0000 Message-ID: <5650E5BB.6020404@simon.arlott.org.uk> References: <5650BFD6.5030700@simon.arlott.org.uk> <5650C08C.6090300@simon.arlott.org.uk> <5650E2FA.6090408@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5650E2FA.6090408-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Ralf Baechle , Thomas Gleixner , Jason Cooper , Marc Zyngier , Kevin Cernekee , Florian Fainelli , Wim Van Sebroeck , Miguel Gaio , Maxime Bizon , Linux Kernel Mailing List , linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala List-Id: devicetree@vger.kernel.org On 21/11/15 21:32, Guenter Roeck wrote: > On 11/21/2015 11:05 AM, Simon Arlott wrote: >> Convert bcm63xx_wdt to use WATCHDOG_CORE and add a device tree binding. >> >> Adds support for the time left value and provides a more effective >> interrupt handler based on the watchdog warning interrupt behaviour. >> >> This removes the unnecessary software countdown timer and replaces the >> use of bcm63xx_timer with a normal interrupt when not using mach-bcm63xx. >> > > Hi Simon, > > this is really doing a bit too much in a single patch. > Conversion to the watchdog infrastructure should probably be > the first step, followed by further optimizations and improvements. I'll split it into two patches, but that won't remove the need for #ifdefs. > In general, it would be great if we can avoid #ifdef in the code. > Maybe there is some other means to determine if one code path > needs to be taken or another. The driver may be part of a > multi-platform image, and #ifdefs in the code make that all > but impossible. Besides, it makes the code really hard to read > and understand. It's impossible to avoid the #ifdefs because the driver needs to support mach-bmips while still supporting mach-bcm63xx. I don't think they make it too difficult to understand. Until there are device tree supporting drivers for everything mach-bcm63xx needs, it can't be removed. > We have some infrastructure changes in the works which will move > the need for soft-timers from individual drivers into the watchdog core. > Would this possibly be helpful here ? The timer-driven watchdog ping > seems to accomplish pretty much the same. There is no need for a software timer. This is not a timer-driven watchdog ping, there is an unmaskable timer interrupt when the watchdog timer has less than 50% remaining. -- Simon Arlott -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html