From: Christian Hewitt Date: Sat, 27 Jun 2026 13:12:05 +0000 (+0000) Subject: ASoC: meson: aiu: fifo-spdif: soft reset the S/PDIF datapath on start/stop X-Git-Tag: v7.2-rc4~31^2~6^2~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b59c53c8adc2b522327407af5e1793a65b67e4b;p=thirdparty%2Fkernel%2Flinux.git ASoC: meson: aiu: fifo-spdif: soft reset the S/PDIF datapath on start/stop The I2S FIFO soft-resets its fast domain on start (AIU_RST_SOFT bit 0 + AIU_I2S_SYNC read in aiu_fifo_i2s_trigger), mirroring the downstream vendor driver's audio_out_i2s_enable(). The S/PDIF FIFO has no equivalent: it only toggles the IEC958 DCU, so a stale datapath FIFO can be replayed, producing the "machine gun noise" buffer underrun - on start when switching outputs, and on stop when playback ends. The latter is audible on devices with an always-on S/PDIF-fed DAC (e.g. the ES7144 on the WeTek Play2). The vendor driver resets the IEC958 fast domain (AIU_RST_SOFT bit 2) on both enable and disable (audio_hw_958_enable), and when reconfiguring (audio_hw_958_reset clears AIU_958_DCU_FF_CTRL then resets). Do the same: reset before enabling the DCU on start, and before disabling on stop. Fixes: 6ae9ca9ce986bf ("ASoC: meson: aiu: add i2s and spdif support") Signed-off-by: Christian Hewitt Reviewed-by: Martin Blumenstingl Link: https://patch.msgid.link/20260627131205.808800-1-christianshewitt@gmail.com Signed-off-by: Mark Brown --- diff --git a/sound/soc/meson/aiu-fifo-spdif.c b/sound/soc/meson/aiu-fifo-spdif.c index e0e00ec026dc..a9861c5d6637 100644 --- a/sound/soc/meson/aiu-fifo-spdif.c +++ b/sound/soc/meson/aiu-fifo-spdif.c @@ -24,6 +24,7 @@ #define AIU_MEM_IEC958_CONTROL_MODE_16BIT BIT(7) #define AIU_MEM_IEC958_CONTROL_MODE_LINEAR BIT(8) #define AIU_MEM_IEC958_BUF_CNTL_INIT BIT(0) +#define AIU_RST_SOFT_958_FAST BIT(2) #define AIU_FIFO_SPDIF_BLOCK 8 @@ -68,11 +69,15 @@ static int fifo_spdif_trigger(struct snd_pcm_substream *substream, int cmd, case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + snd_soc_component_write(component, AIU_RST_SOFT, + AIU_RST_SOFT_958_FAST); fifo_spdif_dcu_enable(component, true); break; case SNDRV_PCM_TRIGGER_SUSPEND: case SNDRV_PCM_TRIGGER_PAUSE_PUSH: case SNDRV_PCM_TRIGGER_STOP: + snd_soc_component_write(component, AIU_RST_SOFT, + AIU_RST_SOFT_958_FAST); fifo_spdif_dcu_enable(component, false); break; default: