* Tomi Valkeinen <tomi.valkeinen@xxxxxx> [140509 00:39]: > On 30/04/14 02:52, Tony Lindgren wrote: > > Otherwise we can get often errors like the following and the > > display won't come on: > > > > omapdss APPLY error: FIFO UNDERFLOW on gfx, disabling the overlay > > omapdss APPLY error: SYNC_LOST on channel lcd, restarting > > the output with video overlays disabled > > > > There are some earlier references to this issue: > > > > http://www.spinics.net/lists/linux-omap/msg59511.html > > http://www.spinics.net/lists/linux-omap/msg59724.html > > Those don't sound like the same issue, but it's hard to say. What kind > of clock rates do you get? Cat you paste debugfs/omapdss/clk, with and > without this patch? Without this patch: # cat /sys/kernel/debug/omapdss/clk [ 24.833831] DSS: dss_runtime_get [ 24.837554] DSS: dss_runtime_put [ 24.840972] DISPC: dispc_runtime_get [ 24.844757] DISPC: dispc_runtime_put - DSS - DSS_FCK (DSS1_ALWON_FCLK) = 57600000 - DISPC - dispc fclk source = DSS_FCK (DSS1_ALWON_FCLK) fck 57600000 - LCD - LCD clk source = DSS_FCK (DSS1_ALWON_FCLK) lck 57600000 lck div 1 pck 19200000 pck div 3 With this patch: # cat /sys/kernel/debug/omapdss/clk [ 34.580688] DSS: dss_runtime_get [ 34.584197] DSS: dss_runtime_put [ 34.587768] DISPC: dispc_runtime_get [ 34.591552] DISPC: dispc_runtime_put - DSS - DSS_FCK (DSS1_ALWON_FCLK) = 108000000 - DISPC - dispc fclk source = DSS_FCK (DSS1_ALWON_FCLK) fck 108000000 - LCD - LCD clk source = DSS_FCK (DSS1_ALWON_FCLK) lck 108000000 lck div 1 pck 18000000 pck div 6 > What resolution do you have? If it's a very high resolution (say, DVI > output to a monitor), it could just be an issue of > not-enough-memory-bandwidth. This is just the 3730-evm with the Sharp VGA panel mentioned in this series. > > It seems that it's safe to set the lower values even for 3630. > > If we can confirm that 3630 works with the higher values > > reliably we can add further detection. > > > > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > > --- > > drivers/video/fbdev/omap2/dss/dss.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/video/fbdev/omap2/dss/dss.c b/drivers/video/fbdev/omap2/dss/dss.c > > index d55266c..ad6561f 100644 > > --- a/drivers/video/fbdev/omap2/dss/dss.c > > +++ b/drivers/video/fbdev/omap2/dss/dss.c > > @@ -707,9 +707,10 @@ static const struct dss_features omap34xx_dss_feats __initconst = { > > .dpi_select_source = &dss_dpi_select_source_omap2_omap3, > > }; > > > > +/* Supposedly 3630 can use div 32 mult 2, but that needs to be rechecked */ > > static const struct dss_features omap3630_dss_feats __initconst = { > > - .fck_div_max = 32, > > - .dss_fck_multiplier = 1, > > + .fck_div_max = 16, > > + .dss_fck_multiplier = 2, > > These values tell about the clock hardware, they are not settings that > can be changed to change the clock. OMAP3630 has a fixed x2 multiplier > and a divider with maximum value of 16. > > Tomi > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
