Messages in this thread | | | Subject | Re: [PATCH v4] clocksource: arch_timer: Allow the device tree to specify uninitialized timer registers | From | Yingjoe Chen <> | Date | Thu, 27 Nov 2014 10:27:04 +0800 |
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Hi,
On Wed, 2014-11-26 at 08:14 -0800, Doug Anderson wrote: > Yingjoe, > > On Wed, Nov 26, 2014 at 6:41 AM, Yingjoe Chen <yingjoe.chen@mediatek.com> wrote: > > Sorry for the (very) late reply. > > I just realize today MT8135 need this and the other patch [1] to boot > > SMP correctly. I've applied both patches and they works fine. Thanks :) > > Excellent. It's helpful to include a Tested-by: tag in your email. > You'd have a line with just "Tested-by: Yingjoe Chen > <yingjoe.chen@mediatek.com>"
sure, here's my tested-by for the 2 patches
Tested-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
I'll remember to add it next time :)
> > However, I'm not sure if we really need to add new property. > > arm_arch_timer driver will only use virtual timer when virtual PPI > > interrupt is provided, so the following patch to timer dtsi will also > > works. I think if the firmware doesn't support virtual timer, it make > > sense to not supply virtual interrupt. > > > > timer { > > compatible = "arm,armv7-timer"; > > interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>, > > - <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>, > > - <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>, > > - <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>; > > + <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>; > > clock-frequency = <13000000>; > > }; > > Once you have Sonny's patch then I believe that the above would work. > However we rejected something like this because device tree is > supposed to describe the hardware. The hardware really does provide > the virtual timer interrupts and they really are at PPI 11 and PPI 10. > It's just that firmware doesn't handle things properly so they can't > be used. > > NOTE: If we add the "arm,cpu-registers-not-fw-configured" to the > device tree and firmware actually works out how to configure things > (like if somehow has firmware that has a hypervisor) then it can > easily remove this device tree property before calling through to the > kernel. It would be much harder for the firmware to add back in the > "PPI 11" and "PPI 10" entries to the timer. > > -Doug
I see your point, that's good for me then. Thanks.
Joe.C
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