Re: [PATCH 1/1] clk: composite: Fix 'switching' to same clock

From: Martin Blumenstingl
Date: Wed Nov 03 2021 - 17:13:43 EST


Hi Alexander,

On Wed, Nov 3, 2021 at 1:24 PM Alexander Stein
<alexander.stein@xxxxxxxxxxxxxxx> wrote:
>
> During commit 6594988fd625 ("clk: composite: Use rate_ops.determine_rate
> when also a mux is available") setting req->best_parent_hw got lost,
> so best_parent_hw stays NULL during switch to the same parent. This
> results in the (debug) message:
> clk_calc_new_rates: lcdif_pixel not gated but wants to reparent
> and the following rate change is dropped.
Thanks for investigating and fixing this!

note to myself: only clocks with CLK_SET_RATE_NO_REPARENT are affected.
This might be the reason why it wasn't spotted on Rockchip SoCs (yet).
I have Cc'ed Alex and Chen-Yu in case they're investigating breakage
on Rockchip SoCs with linux-next

> Fixes: 6594988fd625 ("clk: composite: Use rate_ops.determine_rate when also a mux is available")
> Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>


Best regards,
Martin