From b11d26660dff8d7430892008616452dc8e5fb0f3 Mon Sep 17 00:00:00 2001 From: Jerome Brunet Date: Fri, 26 Apr 2024 17:29:38 +0200 Subject: [PATCH] ASoC: meson: axg-fifo: use threaded irq to check periods With the AXG audio subsystem, there is a possible random channel shift on TDM capture, when the slot number per lane is more than 2, and there is more than one lane used. The problem has been there since the introduction of the axg audio support but such scenario is pretty uncommon. This is why there is no loud complains about the problem. Solving the problem require to make the links non-atomic and use the trigger() callback to start FEs and BEs in the appropriate order. This was tried in the past and reverted because it caused the block irq to sleep while atomic. However, instead of reverting, the solution is to call snd_pcm_period_elapsed() in a non atomic context. Use the bottom half of a threaded IRQ to do so. Fixes: 6dc4fa179fb8 ("ASoC: meson: add axg fifo base driver") Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20240426152946.3078805-2-jbrunet@baylibre.com Signed-off-by: Mark Brown --- sound/soc/meson/axg-fifo.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/sound/soc/meson/axg-fifo.c b/sound/soc/meson/axg-fifo.c index bebee0ca8e38..ecb3eb7a9723 100644 --- a/sound/soc/meson/axg-fifo.c +++ b/sound/soc/meson/axg-fifo.c @@ -204,18 +204,26 @@ static irqreturn_t axg_fifo_pcm_irq_block(int irq, void *dev_id) unsigned int status; regmap_read(fifo->map, FIFO_STATUS1, &status); - status = FIELD_GET(STATUS1_INT_STS, status); - if (status & FIFO_INT_COUNT_REPEAT) - snd_pcm_period_elapsed(ss); - else - dev_dbg(axg_fifo_dev(ss), "unexpected irq - STS 0x%02x\n", - status); - - /* Ack irqs */ axg_fifo_ack_irq(fifo, status); - return IRQ_RETVAL(status); + /* Use the thread to call period elapsed on nonatomic links */ + if (status & FIFO_INT_COUNT_REPEAT) + return IRQ_WAKE_THREAD; + + dev_dbg(axg_fifo_dev(ss), "unexpected irq - STS 0x%02x\n", + status); + + return IRQ_NONE; +} + +static irqreturn_t axg_fifo_pcm_irq_block_thread(int irq, void *dev_id) +{ + struct snd_pcm_substream *ss = dev_id; + + snd_pcm_period_elapsed(ss); + + return IRQ_HANDLED; } int axg_fifo_pcm_open(struct snd_soc_component *component, @@ -243,8 +251,9 @@ int axg_fifo_pcm_open(struct snd_soc_component *component, if (ret) return ret; - ret = request_irq(fifo->irq, axg_fifo_pcm_irq_block, 0, - dev_name(dev), ss); + ret = request_threaded_irq(fifo->irq, axg_fifo_pcm_irq_block, + axg_fifo_pcm_irq_block_thread, + IRQF_ONESHOT, dev_name(dev), ss); if (ret) return ret;