releases/4.19.51/drm-pl111-initialize-clock-spinlock-early.patch

   1 From ae5788f0fcdb418b4cfe2528954e50b783d3620b Mon Sep 17 00:00:00 2001
   2 From: Guenter Roeck <linux@roeck-us.net>
   3 Date: Mon, 13 May 2019 07:46:21 -0700
   4 Subject: drm/pl111: Initialize clock spinlock early
   5
   6 [ Upstream commit 3e01ae2612bdd7975c74ec7123d7f8f5e6eed795 ]
   7
   8 The following warning is seen on systems with broken clock divider.
   9
  10 INFO: trying to register non-static key.
  11 the code is fine but needs lockdep annotation.
  12 turning off the locking correctness validator.
  13 CPU: 0 PID: 1 Comm: swapper Not tainted 5.1.0-09698-g1fb3b52 #1
  14 Hardware name: ARM Integrator/CP (Device Tree)
  15 [<c0011be8>] (unwind_backtrace) from [<c000ebb8>] (show_stack+0x10/0x18)
  16 [<c000ebb8>] (show_stack) from [<c07d3fd0>] (dump_stack+0x18/0x24)
  17 [<c07d3fd0>] (dump_stack) from [<c0060d48>] (register_lock_class+0x674/0x6f8)
  18 [<c0060d48>] (register_lock_class) from [<c005de2c>]
  19         (__lock_acquire+0x68/0x2128)
  20 [<c005de2c>] (__lock_acquire) from [<c0060408>] (lock_acquire+0x110/0x21c)
  21 [<c0060408>] (lock_acquire) from [<c07f755c>] (_raw_spin_lock+0x34/0x48)
  22 [<c07f755c>] (_raw_spin_lock) from [<c0536c8c>]
  23         (pl111_display_enable+0xf8/0x5fc)
  24 [<c0536c8c>] (pl111_display_enable) from [<c0502f54>]
  25         (drm_atomic_helper_commit_modeset_enables+0x1ec/0x244)
  26
  27 Since commit eedd6033b4c8 ("drm/pl111: Support variants with broken clock
  28 divider"), the spinlock is not initialized if the clock divider is broken.
  29 Initialize it earlier to fix the problem.
  30
  31 Fixes: eedd6033b4c8 ("drm/pl111: Support variants with broken clock divider")
  32 Cc: Linus Walleij <linus.walleij@linaro.org>
  33 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  34 Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
  35 Link: https://patchwork.freedesktop.org/patch/msgid/1557758781-23586-1-git-send-email-linux@roeck-us.net
  36 Signed-off-by: Sasha Levin <sashal@kernel.org>
  37 ---
  38  drivers/gpu/drm/pl111/pl111_display.c | 5 +++--
  39  1 file changed, 3 insertions(+), 2 deletions(-)
  40
  41 diff --git a/drivers/gpu/drm/pl111/pl111_display.c b/drivers/gpu/drm/pl111/pl111_display.c
  42 index 754f6b25f265..6d9f78612dee 100644
  43 --- a/drivers/gpu/drm/pl111/pl111_display.c
  44 +++ b/drivers/gpu/drm/pl111/pl111_display.c
  45 @@ -531,14 +531,15 @@ pl111_init_clock_divider(struct drm_device *drm)
  46                 dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
  47                 return PTR_ERR(parent);
  48         }
  49 +
  50 +       spin_lock_init(&priv->tim2_lock);
  51 +
  52         /* If the clock divider is broken, use the parent directly */
  53         if (priv->variant->broken_clockdivider) {
  54                 priv->clk = parent;
  55                 return 0;
  56         }
  57         parent_name = __clk_get_name(parent);
  58 -
  59 -       spin_lock_init(&priv->tim2_lock);
  60         div->init = &init;
  61
  62         ret = devm_clk_hw_register(drm->dev, div);
  63 --
  64 2.20.1
  65