Micha Nelissen [off-list ref] wrote:

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Alexandre Bounine wrote:

quoted

1. Using one storage location common for switches and endpoints

eliminates

quoted

unnecessary device type checks during maintenance access operations.
While destination IDs and hop counts have different meaning for

endpoints and

quoted

switches, this does not prevent us from storing them in the primary

RIO device

quoted

structure (rio_dev) for both types.

=20
How can you say this? The two variables have different meanings, this
logically implies you can't merge them. So how do you say 'this does

not

prevent us from ...' without providing a reason?

Looks like I formulated it bad - better would be: they have different
interpretation by hardware but logically in RapidIO they have single
role - destid/hopcount are a device coordinates in the RIO network used
to access that device.

quoted

2. Convert RIO switch device structures (rio_dev + rio_switch) into

single

quoted

allocation unit. This change is based on the fact that RIO switches

are using

quoted

common RIO device objects anyway. Allocating RIO switch objects as

RIO devices

quoted

with added space for switch information simplifies handling of RIO

switch device

quoted

objects.

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I still don't think that's a good idea because the rdev->rswitch

pointer

can be defined to point to the switch that a given rio_dev is

connected

to. This is useful for quick lookups. How else can to know to which
switch a given device is connected?

rdev->rswitch is not a pointer to the entire switch device object - it
is a pointer to the switch specific extension associated with given
rio_dev (if applicable). There is no other role for rdev->rswitch.

Why would you keep a pointer to device data extension instead of the
pointer to attached device object itself?

BTW, I have back and forward links added in previous patches and only
one link that may be added later is a forward link from mport to the
attached rio_dev (ptr to rio_switch will not work here because it can be
switchless connection). But this reference has to be added into
rio_mport.
=20
Alex.