Messages in this thread | | | Date | Mon, 28 May 2018 17:50:42 +0200 | From | Sebastian Reichel <> | Subject | Re: [PATCHv4 1/2] ARM: imx53: add secure-reg-access support for PMU |
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Hi,
On Mon, May 28, 2018 at 03:20:35PM +0800, Shawn Guo wrote: > On Mon, May 28, 2018 at 08:41:31AM +0200, Sebastian Reichel wrote: > > > Are you saying this is a very specific setup required by i.MX53 only? > > > > Yes, all other SoCs supported by Linux ARM PMU counters driver can > > just use the registers without having to enable platform specific > > bits first. > > > > > In that case, I can live with it. > > > > What about the DT node? I did not add it, since this is a i.MX53 > > specific workaround anyways. > > What you are adding here is secure-reg-access property, which has an > defined meaning in PMU binding doc. I'm not really sure if it's > appropriate to use the property as a condition for DBGEN bit setup. > Or can we set up the bit regardless of the property?
The description for DBGEN bit is:
> Debug enable. This allows the user to manually activate clocks > within the debug system. This register bit directly controls the > platform's dbgen_out output signal which connects to the DAP_SYS to > enable all debug clocks. Once enabled, the clocks cannot be disabled > except by asserting the disable_trace input of the DAP_SYS.
I only enable this bit when the kernel configuration allows using the PMU, since otherwise we do not need the clocks in the debug system. This limits any potential side-effects of this patchset.
-- Sebastian [unhandled content-type:application/pgp-signature] | |