This is a note to let you know that I've just added the patch titled
ASoC: meson: axg-tdm-interface: fix mclk setup without mclk-fs
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
asoc-meson-axg-tdm-interface-fix-mclk-setup-without-.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 46bca75b79cc53ac0e62f2c83748ff03a4305cbc
Author: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Date: Fri Feb 23 18:51:07 2024 +0100
ASoC: meson: axg-tdm-interface: fix mclk setup without mclk-fs
[ Upstream commit e3741a8d28a1137f8b19ae6f3d6e3be69a454a0a ]
By default, when mclk-fs is not provided, the tdm-interface driver
requests an MCLK that is 4x the bit clock, SCLK.
However there is no justification for this:
* If the codec needs MCLK for its operation, mclk-fs is expected to be set
according to the codec requirements.
* If the codec does not need MCLK the minimum is 2 * SCLK, because this is
minimum the divider between SCLK and MCLK can do.
Multiplying by 4 may cause problems because the PLL limit may be reached
sooner than it should, so use 2x instead.
Fixes: d60e4f1e4be5 ("ASoC: meson: add tdm interface driver")
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Link: https://msgid.link/r/20240223175116.2005407-2-jbrunet@xxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/soc/meson/axg-tdm-interface.c b/sound/soc/meson/axg-tdm-interface.c
index 01cc551a8e3fa..2a7ea41fc49e5 100644
--- a/sound/soc/meson/axg-tdm-interface.c
+++ b/sound/soc/meson/axg-tdm-interface.c
@@ -258,8 +258,8 @@ static int axg_tdm_iface_set_sclk(struct snd_soc_dai *dai,
srate = iface->slots * iface->slot_width * params_rate(params);
if (!iface->mclk_rate) {
- /* If no specific mclk is requested, default to bit clock * 4 */
- clk_set_rate(iface->mclk, 4 * srate);
+ /* If no specific mclk is requested, default to bit clock * 2 */
+ clk_set_rate(iface->mclk, 2 * srate);
} else {
/* Check if we can actually get the bit clock from mclk */
if (iface->mclk_rate % srate) {
