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.

Thanks, Sasha

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

From 2fa74713744dc5e908fff851c20f5f89fd665fb7 Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi peter.ujfalusi@linux.intel.com Date: Wed, 17 Dec 2025 16:39:38 +0200 Subject: [PATCH] ASoC: SOF: ipc4-control: If there is no data do not send bytes update

When the bytes control have no data (payload) then there is no need to send an IPC message as there is nothing to send.

Fixes: a062c8899fed ("ASoC: SOF: ipc4-control: Add support for bytes control get and put") Cc: stable@vger.kernel.org Signed-off-by: Peter Ujfalusi peter.ujfalusi@linux.intel.com Reviewed-by: Seppo Ingalsuo seppo.ingalsuo@linux.intel.com Reviewed-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com Reviewed-by: Bard Liao yung-chuan.liao@linux.intel.com Reviewed-by: Kai Vehmanen kai.vehmanen@linux.intel.com Link: https://patch.msgid.link/20251217143945.2667-2-peter.ujfalusi@linux.intel.co... Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/sof/ipc4-control.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/sound/soc/sof/ipc4-control.c b/sound/soc/sof/ipc4-control.c index 976a4794d6100..0a05f66ec7d92 100644 --- a/sound/soc/sof/ipc4-control.c +++ b/sound/soc/sof/ipc4-control.c @@ -412,8 +412,16 @@ static int sof_ipc4_set_get_bytes_data(struct snd_sof_dev *sdev, int ret = 0;

/* Send the new data to the firmware only if it is powered up */ - if (set && !pm_runtime_active(sdev->dev)) - return 0; + if (set) { + if (!pm_runtime_active(sdev->dev)) + return 0; + + if (!data->size) { + dev_dbg(sdev->dev, "%s: No data to be sent.\n", + scontrol->name); + return 0; + } + }

msg->extension = SOF_IPC4_MOD_EXT_MSG_PARAM_ID(data->type);