Re: [PATCH 4/5] clk: qcom: Add camera clock controller driver for SM8150
From: Stephen Boyd
Date: Fri Apr 05 2024 - 17:32:23 EST
Quoting Satya Priya Kakitapalli (Temp) (2024-04-04 23:27:29)
>
> On 3/2/2024 9:43 PM, Bryan O'Donoghue wrote:
> >
> > Alternatively switch on the always-on clocks before the really_probe()
> > but then roll back in a probe_err: goto
> >
> > probe_err:
> > remap_bits_update(regmap, 0xc1e4, BIT(0), 0);
> > pm_runtime_put_sync(&pdev->dev);
> >
> > There may be corner cases where always-on has to happen before
> > really_probe() I suppose but as a general pattern the above should be
> > how we go.
> >
>
> I have rechecked this and see that this clock is PoR ON (i.e BIT(0) is
> set upon power ON) and it should be kept always ON as per HW
> recommendation. So even if the probe fails we shouldn't be clearing it
> against the hw recommendation. We are setting the bit here again to make
> sure it is set when the driver probes.
>
Yes, always on clks should always be on. We don't turn them off if the
driver fails to probe. We should probably print a warning or something
if the register write fails, but since this is mmio it won't fail, so
just make sure they're on and move on.