[Letux-kernel] Status 5.0-rc2 on Pyra

Tony Lindgren tony at atomide.com
Fri Jan 18 21:01:43 CET 2019

* Tony Lindgren <tony at atomide.com> [190117 14:28]:
> * H. Nikolaus Schaller <hns at goldelico.com> [190117 11:07]:
> > This seems to break dmtimer/pwm mode for timer9 which
> > we use for driving display backlight while timer8
> > for keyboard backlight still works.
> Oops sorry about that.
> > Is there an upcoming patch not yet merged in 5.0-rc2 or
> > what makes the difference in 5.0 between timer8 and timer9?
> I need to look. Sounds like there might be some optional clock
> missing in the dts. I'll take a look.
> > PS: the symptom is that we don't even see a /sys/class/backlight
> > node for the display backlight [2].

Adding Tero and linux-omap to Cc.

Nikolaus, care to try the below patch with also timer9 configured
in your board specific dts file depending what the timer source
clock should be:

&timer9 {
	assigned-clocks = <&l4_per_clkctrl OMAP5_TIMER9_CLKCTRL 24>;
	assigned-clock-parents = <&sys_clkin>;

If that works you might as well configure it for timer8 too
for future :)

Earlier we had TIMER9_CLKCTRL bit 0 have TIMER9_CLKCTRL bit 24
as it's parent. But I think we actually have bit 0 as the module
clock and bit 24 as the timer functional clock. So bit 24 is not
a parent of bit 0.

Tero can you check the above assumption?

If that's not the case then we need more patching..



8< ----------------
diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -154,6 +154,10 @@ static int omap_dm_timer_of_set_source(struct omap_dm_timer *timer)
 	if (IS_ERR(parent))
 		return -ENODEV;
+	/* Bail out if both clocks point to fck */
+	if (clk_is_match(parent, timer->fclk))
+		return 0;
 	ret = clk_set_parent(timer->fclk, parent);
 	if (ret < 0)
 		pr_err("%s: failed to set parent\n", __func__);

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