As reported on this [0] mpll series, We are observing a lot of jitter on the MPLL outputs of the g12a. No such jitter is seen on gx family. On the axg family, only MPLL2 seems affected.
The jitter can be as high as +/- 4%. This is a problem for audio application. This may cause distortion on i2s and completely break SPDIF. After exchanging with Amlogic, it seems he have activated (by mistake) the 'spread spectrum' feature. This patchset properly set the bit responsible for the spread spectrum in the mpll driver and add the required correction in the related clock controllers. Jerome Brunet (3): clk: meson: mpll: properly handle spread spectrum clk: meson: gxbb: no spread spectrum on mpll0 clk: meson: axg: spread spectrum is on mpll2 drivers/clk/meson/axg.c | 10 +++++----- drivers/clk/meson/clk-mpll.c | 9 ++++++--- drivers/clk/meson/clk-mpll.h | 1 + drivers/clk/meson/gxbb.c | 5 ----- 4 files changed, 12 insertions(+), 13 deletions(-) -- 2.20.1