Messages in this thread | | | Date | Thu, 5 Nov 2015 22:35:57 +0800 | Subject | Re: [Linaro-acpi] [PATCH v8 5/5] Watchdog: introduce ARM SBSA watchdog driver | From | Fu Wei <> |
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Hi Timur,
On 5 November 2015 at 22:08, Timur Tabi <timur@codeaurora.org> wrote: > Fu Wei wrote: >> >> 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. >> >> 214s means your system counter is approximately at 20MHz which is in >> the range of (10MHz ~ 400MHz) >> >> SBSA 2.3 Page 13 : >> The System Counter (of the Generic Timer) shall run at a minimum >> frequency of 10MHz and maximum of >> 400MHz. > > > Thanks, that explains a lot. > > If we expected customers to have a lower system counter frequency, then we > wouldn't have to worry about the timeouts being too short. It seems to me > that the SBSA spec says that if you want a longer timeout, you have to lower > the frequency.
Did you really read the "Note" above???????? OK, let me paste it again and again:
SBSA 2.3 Page 23 : If a larger watch period is required then the compare value can be programmed directly into the compare value register.
> We shouldn't be complicating the driver because some > customers might not follow the spec.
OK it this customer might not follow the spec, that watchdog is not a SBSA watchdog, So please don't use SBSA watchdog driver on that non-SBSA watchdog device, Thanks a lot
> > > -- > Sent by an employee of the Qualcomm Innovation Center, Inc. > The Qualcomm Innovation Center, Inc. is a member of the > Code Aurora Forum, hosted by The Linux Foundation.
-- 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
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