On Fri, 26 Jan 2024 at 00:56, Joe Komlodi <koml...@google.com> wrote:
>
> It's possible for a reset to come in the middle of a transaction, which
> causes the bus to be in an old state when a new transaction comes in.
>
> Signed-off-by: Joe Komlodi <koml...@google.com>
> ---
> hw/i2c/core.c | 30 +++++++++++++++++++++++++-----
> include/hw/i2c/i2c.h | 6 +++++-
> 2 files changed, 30 insertions(+), 6 deletions(-)
>
> diff --git a/hw/i2c/core.c b/hw/i2c/core.c
> index 4cf30b2c86..def4f134d0 100644
> --- a/hw/i2c/core.c
> +++ b/hw/i2c/core.c
> @@ -23,11 +23,31 @@ static Property i2c_props[] = {
> DEFINE_PROP_END_OF_LIST(),
> };
>
> -static const TypeInfo i2c_bus_info = {
> - .name = TYPE_I2C_BUS,
> - .parent = TYPE_BUS,
> - .instance_size = sizeof(I2CBus),
> -};
> +static void i2c_bus_enter_reset(Object *obj, ResetType type)
> +{
> + I2CBus *bus = I2C_BUS(obj);
> + I2CNode *node, *next;
> +
> + bus->broadcast = false;
> + QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
> + QLIST_REMOVE(node, next);
> + g_free(node);
> + }
Doesn't it confuse the device that's partway through a
transaction if we just forget about the transaction entirely
without terminating it somehow? I'm not sure what real hardware
does in this situation, though.
> +}
> +
> +static void i2c_bus_class_init(ObjectClass *klass, void *data)
> +{
> + ResettableClass *rc = RESETTABLE_CLASS(klass);
> + rc->phases.enter = i2c_bus_enter_reset;
> +}
> +
> + static const TypeInfo i2c_bus_info = {
> + .name = TYPE_I2C_BUS,
> + .parent = TYPE_BUS,
> + .instance_size = sizeof(I2CBus),
> + .class_size = sizeof(I2CBusClass),
> + .class_init = i2c_bus_class_init,
> + };
Looks like you have stray extra spaces in front of this
type definition (which has then caused 'diff' to not notice
that you're only adding fields to the existing struct).
>
> static int i2c_bus_pre_save(void *opaque)
> {
> diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h
> index 2a3abacd1b..420868a269 100644
> --- a/include/hw/i2c/i2c.h
> +++ b/include/hw/i2c/i2c.h
> @@ -64,7 +64,7 @@ struct I2CSlave {
> };
>
> #define TYPE_I2C_BUS "i2c-bus"
> -OBJECT_DECLARE_SIMPLE_TYPE(I2CBus, I2C_BUS)
> +OBJECT_DECLARE_TYPE(I2CBus, I2CBusClass, I2C_BUS)
>
> typedef struct I2CNode I2CNode;
>
> @@ -83,6 +83,10 @@ struct I2CPendingMaster {
> typedef QLIST_HEAD(I2CNodeList, I2CNode) I2CNodeList;
> typedef QSIMPLEQ_HEAD(I2CPendingMasters, I2CPendingMaster) I2CPendingMasters;
>
> +struct I2CBusClass {
> + DeviceClass parent_class;
> +};
This isn't correct -- a FooBusClass's parent_class field
should be a BusClass. But since you don't define any new
fields in it, you don't need to define the struct at all.
Instead, your TypeInfo for the TYPE_I2C_BUS can add a
.class_init member, and leave the .class_size unset
(it will then inherit the class-size from the parent
class, which will be sizeof(BusClass)).
> +
> struct I2CBus {
> BusState qbus;
> I2CNodeList current_devs;
> --
> 2.43.0.429.g432eaa2c6b-goog
thanks
-- PMM
