Re: [PATCH v2 06/24] armv7m: Delete unused "ARM,bitband-memory" devices

[Philippe Mathieu-Daudé]

On 5/28/20 1:04 PM, Markus Armbruster wrote:
> These devices are optional, and enabled by property "enable-bitband".
> armv7m_instance_init() creates them unconditionally, because the
> property has not been set then.  armv7m_realize() realizes them only
> when the property is true.  Works, although it leaves unrealized
> devices hanging around in the QOM composition tree.  Affects machines
> microbit, mps2-an505, mps2-an521, musca-a, and musca-b1.
> 
> Delete the unused devices by making armv7m_realize() unparent them.
> Visible in "info qom-tree"; here's the change for microbit:
> 
>      /machine (microbit-machine)
>        /microbit.twi (microbit.i2c)
>          /microbit.twi[0] (qemu:memory-region)
>        /nrf51 (nrf51-soc)
>          /armv6m (armv7m)
>            /armv7m-container[0] (qemu:memory-region)
>     -      /bitband[0] (ARM,bitband-memory)
>     -        /bitband[0] (qemu:memory-region)
>     -      /bitband[1] (ARM,bitband-memory)
>     -        /bitband[0] (qemu:memory-region)
>            /cpu (cortex-m0-arm-cpu)
> 
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: qemu-arm@nongnu.org
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  hw/arm/armv7m.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c
> index 7da57f56d3..f930619f53 100644
> --- a/hw/arm/armv7m.c
> +++ b/hw/arm/armv7m.c
> @@ -245,8 +245,8 @@ static void armv7m_realize(DeviceState *dev, Error **errp)
>      memory_region_add_subregion(&s->container, 0xe000e000,
>                                  sysbus_mmio_get_region(sbd, 0));
>  
> -    if (s->enable_bitband) {
> -        for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
> +    for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
> +        if (s->enable_bitband) {
>              Object *obj = OBJECT(&s->bitband[i]);
>              SysBusDevice *sbd = SYS_BUS_DEVICE(&s->bitband[i]);
>  
> @@ -265,6 +265,8 @@ static void armv7m_realize(DeviceState *dev, Error **errp)
>  
>              memory_region_add_subregion(&s->container, 
> bitband_output_addr[i],
>                                          sysbus_mmio_get_region(sbd, 0));
> +        } else {
> +            object_unparent(OBJECT(&s->bitband[i]));
>          }
>      }
>  }
>