Messages in this thread | | | Date | Wed, 6 Jul 2011 12:05:48 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH V2 0/6] arm_smp_twd: mpcore_wdt: Fix MPCORE watchdog setup |
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(sorry for reposting - did something wrong with the SMTP configuration and the original mail was rejected as spam by most recipients)
On Wed, Jul 06, 2011 at 11:14:56AM +0100, Russell King - ARM Linux wrote: > On Wed, Jul 06, 2011 at 11:05:51AM +0100, Marc Zyngier wrote: > > On 05/07/11 20:00, Vitaly Kuzmichev wrote: > > > The series of patches fixes various bugs in ARM MPCORE watchdog setup. > > > They also introduce some changes in common ARM_SMP_TWD timer setup code. > > > The PATCH 2/6 adds an exported function to obtain twd timer rate in > > > mpcore_wdt. However, this solution might be unacceptable, and the > > > better is to copy calibration loop and clk_get_rate calling to mpcore_wdt. > > > > My take on this is that the calibration loop should simply be killed > > once Colin's patch using the "smp_twd" clock is merged and relevant > > platforms updated. Once this is done, the watchdog driver should use the > > clock directly, without exporting a symbol. > > Do we know why the calibration was initially introduced? FWIR, it came > from the SMP group in ARM, so I guess they had a reason for it rather > than copying x86.
I think it was introduced because the TWD frequency is half of the CPU frequency but the latter may not be known - boot monitor configuration could change it.
-- Catalin
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