ALSA: ctxfi: Add fallback to default RSR for S/PDIF

[PATCH] ALSA: ctxfi: Add fallback to default RSR for S/PDIF

Posted by Harin Lee 2 months, 1 week ago

spdif_passthru_playback_get_resources() uses atc->pll_rate as the RSR
for the MSR calculation loop. However, pll_rate is only updated in
atc_pll_init() and not in hw_pll_init(), so it remains 0 after the
card init.

When spdif_passthru_playback_setup() skips atc_pll_init() for
32000 Hz, (rsr * desc.msr) always becomes 0, causing the loop to spin
indefinitely.

Add fallback to use atc->rsr when atc->pll_rate is 0. This reflects
the hardware state, since hw_card_init() already configures the PLL
to the default RSR.

Fixes: 8cc72361481f ("ALSA: SB X-Fi driver merge")
Cc: stable@vger.kernel.org
Signed-off-by: Harin Lee <me@harin.net>
---
 sound/pci/ctxfi/ctatc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/pci/ctxfi/ctatc.c b/sound/pci/ctxfi/ctatc.c
index 516c0a12ed9f..02fe09330939 100644
--- a/sound/pci/ctxfi/ctatc.c
+++ b/sound/pci/ctxfi/ctatc.c
@@ -794,7 +794,8 @@ static int spdif_passthru_playback_get_resources(struct ct_atc *atc,
 	struct src *src;
 	int err;
 	int n_amixer = apcm->substream->runtime->channels, i;
-	unsigned int pitch, rsr = atc->pll_rate;
+	unsigned int pitch;
+	unsigned int rsr = atc->pll_rate ? atc->pll_rate : atc->rsr;
 
 	/* first release old resources */
 	atc_pcm_release_resources(atc, apcm);
-- 
2.53.0

Re: [PATCH] ALSA: ctxfi: Add fallback to default RSR for S/PDIF

Posted by Takashi Iwai 2 months, 1 week ago

On Mon, 06 Apr 2026 09:49:13 +0200,
Harin Lee wrote:
> 
> spdif_passthru_playback_get_resources() uses atc->pll_rate as the RSR
> for the MSR calculation loop. However, pll_rate is only updated in
> atc_pll_init() and not in hw_pll_init(), so it remains 0 after the
> card init.
> 
> When spdif_passthru_playback_setup() skips atc_pll_init() for
> 32000 Hz, (rsr * desc.msr) always becomes 0, causing the loop to spin
> indefinitely.
> 
> Add fallback to use atc->rsr when atc->pll_rate is 0. This reflects
> the hardware state, since hw_card_init() already configures the PLL
> to the default RSR.
> 
> Fixes: 8cc72361481f ("ALSA: SB X-Fi driver merge")
> Cc: stable@vger.kernel.org
> Signed-off-by: Harin Lee <me@harin.net>

Applied to for-next branch now.  Thanks.


Takashi