regmap: no indexed caching?
Hi,
indexed caching was removed from regmap (commit 4c691664583ef6a91f9ed0e08a75fbd30a5ffd5c) saying:
There should be no situation where it offers any advantage over rbtree and there are no current users so remove the code for simplicity.
What about devices having just a few registers (4 in my case)? I'd think there are a number of such devices not yet converted to regmap. Is it assumed that the additional overhead from rbtree-caching will make up for the code saved?
Regards,
Wolfram
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Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
Quoted 4 lines · Wolfram Sang
What about devices having just a few registers (4 in my case)? I'd think there are a number of such devices not yet converted to regmap. Is it assumed that the additional overhead from rbtree-caching will make up for the code saved?
There should be vanishingly little overhead from the rbtree, you'll just end up with a single cache node containing all the registers (unless they're widely separated numerically) - it may even be faster as we don't need to search the array looking for the index.