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Re: [Qemu-arm] [Qemu-devel] [PATCH v4 05/10] docs/clocks: add device's c
Re: [Qemu-arm] [Qemu-devel] [PATCH v4 05/10] docs/clocks: add device's clock documentation
Tue, 25 Sep 2018 12:52:10 +0100
On 25 September 2018 at 12:47, Damien Hedde <address@hidden> wrote:
> On 9/25/18 11:36 AM, Peter Maydell wrote:
>> On 17 September 2018 at 09:40, <address@hidden> wrote:
>>> +Outputs must be initialized in the device_reset method to ensure every
>>> +inputs is updated at machine startup.
>> device_reset should not set outputs.
> How do the initialization then ?
> Only alternative I see is to initialize a clock input when it is
> connected to an output.
> If device_reset does not set outputs (which are a direct consequence of
> a internal device state being reset). It means calling device_reset at
> any other point than simulation startup will break things. Is that the
> semantic behind device_reset ?
device_reset's semantics are not great, but basically they are
"power on reset", equivalent to a complete simulation restart.
If a device has some other kind of warm reset triggered by
eg a register write it needs to implement that itself, perhaps
sharing code with the device reset method. A warm reset triggered
by a register write can obviously assert output signals.
I have some thoughts about trying to clean up our reset
semantics which I need to write up later this week.
[Qemu-arm] [PATCH v4 06/10] sysbus: add bus_interface_clock feature to sysbus devices, damien . hedde, 2018/09/17
[Qemu-arm] [PATCH v4 09/10] hw/char/cadence_uart: add clock support, damien . hedde, 2018/09/17
[Qemu-arm] [PATCH v4 02/10] qdev: add clock input&output support to devices., damien . hedde, 2018/09/17
[Qemu-arm] [PATCH v4 07/10] hw/misc/zynq_slcr: use standard register definition, damien . hedde, 2018/09/17
Re: [Qemu-arm] [PATCH v4 00/10] Clock framework API., Peter Maydell, 2018/09/19