Re: [Qemu-devel] [PATCH v2 4/6] hw/sd/pl181: expose a SDBus and connect the SDCard to it

[Peter Maydell <peter.maydell@linaro.org>]

On 6 February 2018 at 12:43, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> Hi Alistair,
>
> On 01/31/2018 01:41 PM, Alistair Francis wrote:
>> On Mon, Jan 22, 2018 at 7:58 PM, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>>> using the sdbus_*() API.
>>>
>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>>> ---
>>>  hw/sd/pl181.c | 31 ++++++++++++++++++++-----------
>>>  1 file changed, 20 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/hw/sd/pl181.c b/hw/sd/pl181.c
>>> index 3ba1f7dd23..ce696c5d7d 100644
>>> --- a/hw/sd/pl181.c
>>> +++ b/hw/sd/pl181.c
>>> @@ -33,6 +33,7 @@ typedef struct PL181State {
>>>      SysBusDevice parent_obj;
>>>
>>>      MemoryRegion iomem;
>>> +    SDBus sdbus;
>>>      SDState *card;
>>
>> Shouludn't card be removed?
>
> Not yet :( It is still used by sd_set_cb() in pl181_reset().

I think you have to change that sd_set_cb() code now.
If you look at sd_cardchange() it uses "is this SD card
object on an SDBus" to determine whether to notify the
controller via the old-API IRQ lines, or using the
set_inserted() and set_readonly() callbacks on the SDBusClass.

> In my first approach [1] I added the SDBus SLAVE/MASTER interfaces and
> the cards inserted/readonly signals were only accessible by the bus, not
> the HCI, leaving the SDCard objects only pluggable to SDBus (removing
> the sdbus_reparent_card() need). But since it was out of scope for the
> UHS cards goal, I kept it for later.

How do you manage to get rid of sdbus_reparent_card()? Raspi
needs it for its weirdo multiplexed SD controller setup, and
AFAIK we don't have a way to say "this thing is hotpluggable
but not by the user" yet...

PS: have you checked that these sd card refactorings don't
accidentally break the monitor "change" and "eject" commands
operating on SD cards ? (They are a bit weird because they
affect which backing file is attached to the SD card object,
rather than actually deleting and recreating the SD card
object.)

thanks
-- PMM