Hi Stephen, On Fri, Apr 30, 2021 at 01:59:39PM -0700, Stephen Boyd wrote: > Quoting Maxime Ripard (2021-04-13 03:13:18) > > Hi, > > > > This is a follow-up of the discussion here: > > https://lore.kernel.org/linux-clk/20210319150355.xzw7ikwdaga2dwhv@gilmour/ > > > > This implements a mechanism to raise and lower clock rates based on consumer > > workloads, with an example of such an implementation for the RaspberryPi4 HDMI > > controller. > > > > There's a couple of things worth discussing: > > > > - The name is in conflict with clk_request_rate, and even though it feels > > like the right name to me, we should probably avoid any confusion > > > > - The code so far implements a policy of always going for the lowest rate > > possible. While we don't have an use-case for something else, this should > > maybe be made more flexible? > > I'm definitely confused how it is different from the > clk_set_rate_exclusive() API and associated > clk_rate_exclusive_get()/clk_rate_exclusive_put(). Can you explain > further the differences in the cover letter here? The exclusive API is meant to prevent the clock rate from changing, allowing a single user to make sure that no other user will be able to change it. What we want here is instead to allow multiple users to be able to express a set of minimum rates and then let the CCF figure out a rate for that clock that matches those constraints (so basically what clk_set_min_rate does), but then does allow for the clock to go back to its initial rate once that constraint is not needed anymore. So I guess it's more akin to clk_set_min_rate with rollback than the exclusive API? Maxime
Attachment:
signature.asc
Description: PGP signature
_______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
