The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x d18ca8635db2f88c17acbdf6412f26d4f6aff414 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024051357-errand-chariot-abc6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

d18ca8635db2 ("ASoC: ti: davinci-mcasp: Fix race condition during probe") 1b4fb70e5b28 ("ASoC: ti: davinci-mcasp: Handle missing required DT properties")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d18ca8635db2f88c17acbdf6412f26d4f6aff414 Mon Sep 17 00:00:00 2001 From: Joao Paulo Goncalves joao.goncalves@toradex.com Date: Wed, 17 Apr 2024 15:41:38 -0300 Subject: [PATCH] ASoC: ti: davinci-mcasp: Fix race condition during probe

When using davinci-mcasp as CPU DAI with simple-card, there are some conditions that cause simple-card to finish registering a sound card before davinci-mcasp finishes registering all sound components. This creates a non-working sound card from userspace with no problem indication apart from not being able to play/record audio on a PCM stream. The issue arises during simultaneous probe execution of both drivers. Specifically, the simple-card driver, awaiting a CPU DAI, proceeds as soon as davinci-mcasp registers its DAI. However, this process can lead to the client mutex lock (client_mutex in soc-core.c) being held or davinci-mcasp being preempted before PCM DMA registration on davinci-mcasp finishes. This situation occurs when the probes of both drivers run concurrently. Below is the code path for this condition. To solve the issue, defer davinci-mcasp CPU DAI registration to the last step in the audio part of it. This way, simple-card CPU DAI parsing will be deferred until all audio components are registered.

Fail Code Path:

simple-card.c: probe starts simple-card.c: simple_dai_link_of: simple_parse_node(..,cpu,..) returns EPROBE_DEFER, no CPU DAI yet davinci-mcasp.c: probe starts davinci-mcasp.c: devm_snd_soc_register_component() register CPU DAI simple-card.c: probes again, finish CPU DAI parsing and call devm_snd_soc_register_card() simple-card.c: finish probe davinci-mcasp.c: *dma_pcm_platform_register() register PCM DMA davinci-mcasp.c: probe finish

Cc: stable@vger.kernel.org Fixes: 9fbd58cf4ab0 ("ASoC: davinci-mcasp: Choose PCM driver based on configured DMA controller") Signed-off-by: Joao Paulo Goncalves joao.goncalves@toradex.com Acked-by: Peter Ujfalusi peter.ujfalusi@gmail.com Reviewed-by: Jai Luthra j-luthra@ti.com Link: https://lore.kernel.org/r/20240417184138.1104774-1-jpaulo.silvagoncalves@gma... Signed-off-by: Mark Brown broonie@kernel.org

diff --git a/sound/soc/ti/davinci-mcasp.c b/sound/soc/ti/davinci-mcasp.c index b892d66f7847..1e760c315521 100644 --- a/sound/soc/ti/davinci-mcasp.c +++ b/sound/soc/ti/davinci-mcasp.c @@ -2417,12 +2417,6 @@ static int davinci_mcasp_probe(struct platform_device *pdev)

mcasp_reparent_fck(pdev);

- ret = devm_snd_soc_register_component(&pdev->dev, &davinci_mcasp_component, - &davinci_mcasp_dai[mcasp->op_mode], 1); - - if (ret != 0) - goto err; - ret = davinci_mcasp_get_dma_type(mcasp); switch (ret) { case PCM_EDMA: @@ -2449,6 +2443,12 @@ static int davinci_mcasp_probe(struct platform_device *pdev) goto err; }

+ ret = devm_snd_soc_register_component(&pdev->dev, &davinci_mcasp_component, + &davinci_mcasp_dai[mcasp->op_mode], 1); + + if (ret != 0) + goto err; + no_audio: ret = davinci_mcasp_init_gpiochip(mcasp); if (ret) {