Re: [PATCH v1 1/1] ASoC: wm8904: Enable FLL when switching an active SYSCLK to FLL

[Charles Keepax]

On Wed, Nov 04, 2026 at 04:58:32PM +0100, Stefano Radaelli wrote:
> From: Stefano Radaelli <stefano.r@xxxxxxxxxxxxx>
> 
> When switching SYSCLK from MCLK to FLL, DAPM may keep SYSCLK powered
> and skip the PRE_PMU event that normally enables the FLL. This leaves
> SYSCLK sourced from a disabled FLL and can cause playback to fail.
> 
> Enable FLL_OSC_ENA and FLL_ENA before selecting FLL as the SYSCLK
> source when WM8904_CLK_SYS_ENA is already set.
> 
> On VAR-SOM-MX8X, playing audio at 48 kHz followed immediately by
> 8 kHz reproduced an I/O error when switching from MCLK to FLL.
> With this change, playback succeeds.
> 
> Co-developed-by: Alexander Herfurtner <alexander.h@xxxxxxxxxxxxx>
> Signed-off-by: Alexander Herfurtner <alexander.h@xxxxxxxxxxxxx>
> Signed-off-by: Stefano Radaelli <stefano.r@xxxxxxxxxxxxx>
> ---

Reviewed-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>

Thanks,
Charles