Re: [PATCH v4 5/7] Watchdog: introduce ARM SBSA watchdog driver
From: Fu Wei <hidden>
Date: 2015-06-10 14:41:17
Also in:
linux-watchdog, lkml
On 10 June 2015 at 22:36, Fu Wei [off-list ref] wrote:
On 10 June 2015 at 22:22, Timur Tabi [off-list ref] wrote:quoted
Fu Wei wrote:quoted
Another weakness of only using WOR is the timeout limited by this 32bit register. 10s @400MHz generic Timer I don't think this limit is good for a server, once the server is in a heavy loadPerhaps, but if that's the limitation of the hardware, then so be it.it is not the real limitation, if we use WCV, SBSA spec has mentioned that. ------ SBSA 2.3-------Page 23 ---------- Note: the watchdog offset register is 32 bits wide. This gives a maximum watch period of around 10s at a system counter frequency of 400MHz. If a larger watch period is required then the compare value can be programmed directly into the compare value register ------ SBSA 2.3-------Page 23 ----------
------ SBSA 2.3-------Page 24 ---------- 0x010 – 0x013 WCV[31:0] 0x014 – 0x017 WCV[63:32] Watchdog compare value. *Read/Write* registers containing the current value in the watchdog compare register. ------ SBSA 2.3-------Page 24 ----------
if some hardware doesn't support writing WCV, that means this hardware is non-standard SBSA watchdog.quoted
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-- 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 -- 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