FAILED: patch "[PATCH] ASoC: fsl: fsl_qmc_audio: Reset audio data pointers on" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 9aa33d5b4a53a1945dd2aee45c09282248d3c98b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025042145-scrunch-freckled-e48e@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 9aa33d5b4a53a1945dd2aee45c09282248d3c98b Mon Sep 17 00:00:00 2001
From: Herve Codina <herve.codina@bootlin.com>
Date: Thu, 10 Apr 2025 11:16:43 +0200
Subject: [PATCH] ASoC: fsl: fsl_qmc_audio: Reset audio data pointers on
 TRIGGER_START event

On SNDRV_PCM_TRIGGER_START event, audio data pointers are not reset.

This leads to wrong data buffer usage when multiple TRIGGER_START are
received and ends to incorrect buffer usage between the user-space and
the driver. Indeed, the driver can read data that are not already set by
the user-space or the user-space and the driver are writing and reading
the same area.

Fix that resetting data pointers on each SNDRV_PCM_TRIGGER_START events.

Fixes: 075c7125b11c ("ASoC: fsl: Add support for QMC audio")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20250410091643.535627-1-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/fsl/fsl_qmc_audio.c b/sound/soc/fsl/fsl_qmc_audio.c
index b2979290c973..5614a8b909ed 100644
--- a/sound/soc/fsl/fsl_qmc_audio.c
+++ b/sound/soc/fsl/fsl_qmc_audio.c
@@ -250,6 +250,9 @@ static int qmc_audio_pcm_trigger(struct snd_soc_component *component,
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		bitmap_zero(prtd->chans_pending, 64);
+		prtd->buffer_ended = 0;
+		prtd->ch_dma_addr_current = prtd->ch_dma_addr_start;
+
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			for (i = 0; i < prtd->channels; i++)
 				prtd->qmc_dai->chans[i].prtd_tx = prtd;