Re: [PATCH RFC 03/16] OPP: Retry failed default single-clock transitions

[Konrad Dybcio]

On 10/14/26 3:35 PM, Dmitry Baryshkov wrote:
> On Wed, Oct 14, 2026 at 02:19:03PM +0200, Konrad Dybcio wrote:
>> From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
>>
>> A failed OPP transition need not leave the clock at the last successful
>> OPP's frequency. If hardware changed before the error, the default
>> single-clock path can subsequently skip a necessary retry because its
> 
> What is a necessary retry? Shouldn't it be: try, rollback if it fails?

The failure scenario is:

opp-table {
	opp-400000000 {
		// low
	};

	opp-1000000000 {
		// high
	};
}';

1. The device is running at Low. OPP caches 400 MHz and the Low OPP.
2. A driver requests High.
- OPP raises the voltage to 0.95 V.
- clk_set_rate(..., 1 GHz) changes the clock, but returns an error
- Assume clk_get_rate() can report the resulting 1 GHz rate.
3. The transition returns an error, so current_opp still points to Low.
4. The caller tries to recover by requesting Low again.

Perhaps I should have included that in the commit message.

Konrad