Re: [PATCH RFC] Watchdog: sbsa_gwdt: Enhance timeout range

From: Guenter Roeck
Date: Thu May 05 2016 - 19:51:26 EST


On 05/05/2016 04:38 PM, Timur Tabi wrote:
Guenter Roeck wrote:
A 32-bit counter is absolutely fine. Letting it run with a 400MHz clock
(or was it 200 MHz ?) is the problem. A resolution of 2.5ns for a watchdog
timer does not really make any sense.

The 10 second limit is based on a 20MHz clock.

Not that a resolution of 50 ns makes sense either, but 4294967296 / 20971520 = 204,
and 20971520 * 10 = 209715200 = 0x0c800000. Where does the resolution get lost ?

Guenter