On Mon, Sep 30, 2019 at 8:39 AM H. Nikolaus Schaller <h...@goldelico.com> wrote: > > > > Am 30.09.2019 um 10:53 schrieb Tero Kristo <t-kri...@ti.com>: > > > > The best action here is probably to drop the max-div value for this clock > > to 16. Can someone check this with their display setup and see what > > happens? Attached patch should do the trick. > > I have checked on GTA04 and OpenPandora (DM3730 resp. OMAP3430) and did not > notice a negative effect. > > (Well, we never see the problem that is discussed here and have built with > CONFIG_OMAP2_DSS_MIN_FCK_PER_PCK=0).
I have never been able to use CONFIG_OMAP2_DSS_MIN_FCK_PER_PCK=0, but I assume it's either a function of pck or a combination of pck with the resolution. Based on Tomi's comment, I assume he's working on the following. Can you also try: diff --git a/drivers/gpu/drm/omapdrm/dss/dss.c b/drivers/gpu/drm/omapdrm/dss/dss.c index 5711b7a720e6..5e584f32ea6a 100644 --- a/drivers/gpu/drm/omapdrm/dss/dss.c +++ b/drivers/gpu/drm/omapdrm/dss/dss.c @@ -1090,7 +1090,7 @@ static const struct dss_features omap34xx_dss_feats = { static const struct dss_features omap3630_dss_feats = { .model = DSS_MODEL_OMAP3, - .fck_div_max = 32, + .fck_div_max = 16, .fck_freq_max = 173000000, .dss_fck_multiplier = 1, .parent_clk_name = "dpll4_ck", Hopefully it doesn't break the 3630 for you, but it fixed my issue with no back trace: [ 9.915588] DSS: set fck to 54000000 [ 9.915618] DISPC: lck = 54000000 (1) [ 9.915649] DISPC: pck = 9000000 (6) [ 9.917633] DISPC: channel 0 xres 480 yres 272 [ 9.917663] DISPC: pck 9000000 I do wonder, however if there is a divider that is higher than 16, but lower than 32. I was able to run fck at 36MHz before with divide by 4 to 9MHz, so I am hoping that by running at 54MHz / 6 doesn't draw more power. I was reading through the datasheet, but I could not find any reference to the max divider. adam > > BR, > Nikolaus >