Re: [PATCH net-next v4 2/8] switchdev: mrp: Extend ring_role_mrp and in_role_mrp

The 02/17/2021 10:34, Vladimir Oltean wrote:

Hi Vladimir,

On Tue, Feb 16, 2021 at 10:41:59PM +0100, Horatiu Vultur wrote:

quoted

Add the member sw_backup to the structures switchdev_obj_ring_role_mrp
and switchdev_obj_in_role_mrp. In this way the SW can call the driver in
2 ways, once when sw_backup is set to false, meaning that the driver
should implement this completely in HW. And if that is not supported the
SW will call again but with sw_backup set to true, meaning that the
HW should help or allow the SW to run the protocol.

For example when role is MRM, if the HW can't detect when it stops
receiving MRP Test frames but it can trap these frames to CPU, then it
needs to return -EOPNOTSUPP when sw_backup is false and return 0 when
sw_backup is true.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 include/net/switchdev.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 465362d9d063..b7fc7d0f54e2 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h

@@ -127,6 +127,7 @@ struct switchdev_obj_ring_role_mrp {
      struct switchdev_obj obj;
      u8 ring_role;
      u32 ring_id;
+     u8 sw_backup;
 };

 #define SWITCHDEV_OBJ_RING_ROLE_MRP(OBJ) \

@@ -161,6 +162,7 @@ struct switchdev_obj_in_role_mrp {
      u32 ring_id;
      u16 in_id;
      u8 in_role;
+     u8 sw_backup;

What was wrong with 'bool'?

Yeah, that would be a better match.

quoted

 };

 #define SWITCHDEV_OBJ_IN_ROLE_MRP(OBJ) \
--
2.27.0

If a driver implements full MRP offload for a ring/interconnect
manager/automanager, should it return -EOPNOTSUPP when sw_backup=false?

In that case it should return 0.
So if the driver can:
- fully support MRP, when sw_backup = false, return 0. Then end of story.
- partially support MRP, when sw_backup = false, return -EOPNOTSUPP,
                         when sw_backup = true, return 0.
- no support at all, return -EOPNOTSUPP.

-- 
/Horatiu