Messages in this thread | | | Date | Wed, 28 Nov 2012 07:16:12 -0600 | From | Mark Langsdorf <> | Subject | Re: [PATCH 6/6 v6] cpufreq, highbank: add support for highbank cpufreq |
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On 11/27/2012 08:32 PM, Shawn Guo wrote: > On Tue, Nov 27, 2012 at 02:04:32PM -0600, Mark Langsdorf wrote: >> Highbank processors depend on the external ECME to perform voltage >> management based on a requested frequency. Communication between the >> A9 cores and the ECME happens over the pl320 IPC channel. > > ... > >> +static int hb_voltage_change(unsigned int freq) >> +{ >> + int i; >> + u32 msg[7]; >> + >> + msg[0] = HB_CPUFREQ_CHANGE_NOTE; >> + msg[1] = freq / 1000; >> + for (i = 2; i < 7; i++) >> + msg[i] = 0; >> + >> + return pl320_ipc_transmit(msg); > > Is it possible to have this handled inside clk_set_rate() call of cpu > clock?
Standard practice is to have cpufreq_set_target() handle voltage transitions and leave clk_set_rate() handle the frequency changes. I'd have to move most of the logic of hb_set_target() into clk_highbank.c:clk_pll_set_rate() and then add extra logic for when cpufreq is not enabled/loaded. I don't think the clk maintainers would take that patch, either.
So no.
--Mark Langsdorf Calxeda, Inc.
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