target/linux/bcm27xx/patches-5.10/950-0717-drm-vc4-hdmi-Make-sure-the-controller-is-powered-up-.patch

   1 From 94bc403a9a7af3bd042ecdc160e6ab0b08331df8 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Fri, 2 Jul 2021 12:03:28 +0200
   4 Subject: [PATCH] drm/vc4: hdmi: Make sure the controller is powered up during
   5  bind
   6
   7 In the bind hook, we actually need the device to have the HSM clock
   8 running during the final part of the display initialisation where we
   9 reset the controller and initialise the CEC component.
  10
  11 Failing to do so will result in a complete, silent, hang of the CPU.
  12
  13 Fixes: 411efa18e4b0 ("drm/vc4: hdmi: Move the HSM clock enable to runtime_pm")
  14 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  15 ---
  16  drivers/gpu/drm/vc4/vc4_hdmi.c | 17 +++++++++++++++--
  17  1 file changed, 15 insertions(+), 2 deletions(-)
  18
  19 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  20 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  21 @@ -2295,6 +2295,18 @@ static int vc4_hdmi_bind(struct device *
  22         if (ret)
  23                 goto err_put_ddc;
  24
  25 +       /*
  26 +        * We need to have the device powered up at this point to call
  27 +        * our reset hook and for the CEC init.
  28 +        */
  29 +       ret = vc4_hdmi_runtime_resume(dev);
  30 +       if (ret)
  31 +               goto err_put_ddc;
  32 +
  33 +       pm_runtime_get_noresume(dev);
  34 +       pm_runtime_set_active(dev);
  35 +       pm_runtime_enable(dev);
  36 +
  37         if (vc4_hdmi->variant->reset)
  38                 vc4_hdmi->variant->reset(vc4_hdmi);
  39
  40 @@ -2306,8 +2318,6 @@ static int vc4_hdmi_bind(struct device *
  41                 clk_prepare_enable(vc4_hdmi->pixel_bvb_clock);
  42         }
  43
  44 -       pm_runtime_enable(dev);
  45 -
  46         drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_TMDS);
  47         drm_encoder_helper_add(encoder, &vc4_hdmi_encoder_helper_funcs);
  48
  49 @@ -2331,6 +2341,8 @@ static int vc4_hdmi_bind(struct device *
  50                              vc4_hdmi_debugfs_regs,
  51                              vc4_hdmi);
  52
  53 +       pm_runtime_put_sync(dev);
  54 +
  55         return 0;
  56
  57  err_free_cec:
  58 @@ -2341,6 +2353,7 @@ err_destroy_conn:
  59         vc4_hdmi_connector_destroy(&vc4_hdmi->connector);
  60  err_destroy_encoder:
  61         drm_encoder_cleanup(encoder);
  62 +       pm_runtime_put_sync(dev);
  63         pm_runtime_disable(dev);
  64  err_put_ddc:
  65         put_device(&vc4_hdmi->ddc->dev);