FAILED: patch "[PATCH] ASoC: ti: davinci-mcasp: Fix race condition during probe" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-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 <[email protected]>.

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-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x d18ca8635db2f88c17acbdf6412f26d4f6aff414
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024051308-sullen-plug-a6fb@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

d18ca8635db2 ("ASoC: ti: davinci-mcasp: Fix race condition during probe") 1b4fb70e5b28 ("ASoC: ti: davinci-mcasp: Handle missing required DT properties") 1125d925990b ("ASoC: ti: davinci-mcasp: Simplify the configuration parameter handling") db8793a39b29 ("ASoC: ti: davinci-mcasp: Remove legacy dma_request parsing") 372c4bd11de1 ("ASoC: ti: davinci-mcasp: Use platform_get_irq_byname_optional") 19f6e424d615 ("ASoC: ti: davinci-mcasp: remove always zero of davinci_mcasp_get_dt_params") f4d95de415b2 ("ASoC: ti: davinci-mcasp: remove redundant assignment to variable ret") 764958f2b523 ("ASoC: ti: davinci-mcasp: Support for auxclk-fs-ratio") 540f1ba7b3a5 ("ASoC: ti: davinci-mcasp: Add support for GPIO mode of the pins") 617547175507 ("ASoC: ti: davinci-mcasp: Move context save/restore to runtime_pm callbacks") f2055e145f29 ("ASoC: ti: Merge davinci and omap directories")
bc1845498531 ("ASoC: davinci-mcasp: Implement configurable dismod handling") ca3d9433349e ("ASoC: davinci-mcasp: Update PDIR (pin direction) register handling") 9c34d023dc35 ("ASoC: omap-mcbsp: Re-arrange files for core McBSP and Sidetone function split") be51c576e849 ("ASoC: omap-mcbsp: Move out the FIFO check from set_threshold and get_delay") 59d177f65f50 ("ASoC: omap-mcbsp: Simplify the mcbsp_start/_stop function parameters") d63a7625a6df ("ASoC: omap-mcbsp: Clean up the interrupt handlers")
c9ece9c29e26 ("ASoC: omap-mcbsp: Skip dma_data.maxburst initialization") dd443a7c0b00 ("ASoC: omap-mcbsp: Clean up dma_data addr initialization code") 2c2596f3ab25 ("ASoC: omap: Remove unused machine driver for AM3517-evm")

thanks,

greg k-h

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

From d18ca8635db2f88c17acbdf6412f26d4f6aff414 Mon Sep 17 00:00:00 2001
From: Joao Paulo Goncalves <[email protected]>
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

index b892d66f7847..1e760c315521 100644
@@ -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) {