queue-4.19/clocksource-timer-ti-dm-fix-pwm-dmtimer-usage-of-fck.patch

   1 From 3bb88457dd0e4d039b1c8a7debf4cd6ae187c87f Mon Sep 17 00:00:00 2001
   2 From: Tony Lindgren <tony@atomide.com>
   3 Date: Tue, 22 Jan 2019 09:03:08 -0800
   4 Subject: clocksource: timer-ti-dm: Fix pwm dmtimer usage of fck reparenting
   5
   6 [ Upstream commit 983a5a43ec254cd5ddf3254db80ca96e8f8bb2a4 ]
   7
   8 Commit 84badc5ec5fc ("ARM: dts: omap4: Move l4 child devices to probe
   9 them with ti-sysc") moved some omap4 timers to probe with ti-sysc
  10 interconnect target module. Turns out this broke pwm-omap-dmtimer
  11 where we now try to reparent the clock to itself with the following:
  12
  13 omap_dm_timer_of_set_source: failed to set parent
  14
  15 With ti-sysc, we can now configure the clock sources in the dts
  16 with assigned-clocks and assigned-clock-parents. So we should be able
  17 to remove omap_dm_timer_of_set_source with clean-up patches later on.
  18 But for now, let's just fix it first by checking if parent and fck
  19 are the same and bail out of so.
  20
  21 Fixes: 84badc5ec5fc ("ARM: dts: omap4: Move l4 child devices to probe them with ti-sysc")
  22 Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
  23 Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
  24 Cc: H. Nikolaus Schaller <hns@goldelico.com>
  25 Cc: Keerthy <j-keerthy@ti.com>
  26 Cc: Ladislav Michl <ladis@linux-mips.org>
  27 Cc: Pavel Machek <pavel@ucw.cz>
  28 Cc: Sebastian Reichel <sre@kernel.org>
  29 Cc: Tero Kristo <t-kristo@ti.com>
  30 Cc: Thierry Reding <thierry.reding@gmail.com>
  31 Cc: Thomas Gleixner <tglx@linutronix.de>
  32 Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
  33 Tested-By: Andreas Kemnade <andreas@kemnade.info>
  34 Tested-By: H. Nikolaus Schaller <hns@goldelico.com>
  35 Signed-off-by: Tony Lindgren <tony@atomide.com>
  36 Signed-off-by: Sasha Levin <sashal@kernel.org>
  37 ---
  38  drivers/clocksource/timer-ti-dm.c | 4 ++++
  39  1 file changed, 4 insertions(+)
  40
  41 diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
  42 index 4cce6b224b87..3ecf84706640 100644
  43 --- a/drivers/clocksource/timer-ti-dm.c
  44 +++ b/drivers/clocksource/timer-ti-dm.c
  45 @@ -154,6 +154,10 @@ static int omap_dm_timer_of_set_source(struct omap_dm_timer *timer)
  46         if (IS_ERR(parent))
  47                 return -ENODEV;
  48
  49 +       /* Bail out if both clocks point to fck */
  50 +       if (clk_is_match(parent, timer->fclk))
  51 +               return 0;
  52 +
  53         ret = clk_set_parent(timer->fclk, parent);
  54         if (ret < 0)
  55                 pr_err("%s: failed to set parent\n", __func__);
  56 --
  57 2.19.1
  58