Re: [PATCH] clk: qcom: gcc-x1e80100: Don't use parking clk_ops for QUPs

[Konrad Dybcio]

On 23.08.2024 2:58 PM, Bryan O'Donoghue wrote:
> Per Stephen Boyd's explanation in the link below, QUP RCG clocks do not
> need to be parked when switching frequency. A side-effect in parking to a
> lower frequency can be a momentary invalid clock driven on an in-use serial
> peripheral.
> 
> This can cause "junk" to spewed out of a UART as a low-impact example. On
> the x1e80100-crd this serial port junk can be observed on linux-next.
> 
> Apply a similar fix to the x1e80100 Global Clock controller to remediate.
> 
> Link: https://lore.kernel.org/all/20240819233628.2074654-3-swboyd@xxxxxxxxxxxx/
> Fixes: 161b7c401f4b ("clk: qcom: Add Global Clock controller (GCC) driver for X1E80100")
> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
> Suggested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
> ---
> I ran into some junk on the x1e80100 serial port and asked around to see if
> someone had already found and fixed.
> 
> Neil pointed me at Stephen's fix for sm8550 which I found is also required
> to fix the same thing x1e80100.
> ---

Reviewed-by: Konrad Dybcio <konradybcio@xxxxxxxxxx>

Mind also fixing up 8650 that seems to have this issue?

Konrad