On 09/19/2017 08:26 AM, Andrea Bolognani wrote:
On Tue, 2017-09-19 at 07:27 -0400, John Ferlan wrote:
First of all, you're removing a number of checks on unrelated symbols that are still used in the code, and if any of those is not present then we shouldn't compile the relevant bits at all.
I checked - up through 4.8 "most" are available. At 4.8 the *ESWITCH* ones were added. Checking for a minimum version for a symbol is something we do in other code under the assumption that any symbol that is in a counted enum/list for a command or structure before it is available. Otherwise, we'd have more symbol and field checking all over the place.
Okay, I see what you were aiminig for now, and I don't disagree with it; however, the rationale was not explained clearly in the original commit message.
OK - I did have it at one point, but the damn commit message got so long I just trimmed out that part...
Second, we're using DEVLINK_CMD_ESWITCH_GET in the code, but as you explain that version is only available in newer kernels.
I think the approach need to be more nuanced:
- use DEVLINK_CMD_ESWITCH_GET or DEVLINK_CMD_ESWITCH_MODE_GET, depending on which on is available, with the former one being the preferred option;
That's another option to what I posted a few moments ago to use:
# ifndef...
Sure, that would work too, and look a little bit better than what I proposed.
So is this methodology preferred over what Jano posts? John