target/linux/bcm27xx/patches-5.15/950-0010-drm-vc4-hdmi-Check-the-device-state-in-prepare.patch

   1 From ba0375640d2d82158600a398181bb9f9c3835d0a Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Fri, 24 Sep 2021 14:27:38 +0200
   4 Subject: [PATCH] drm/vc4: hdmi: Check the device state in prepare()
   5
   6 Even though we already check that the encoder->crtc pointer is there
   7 during in startup(), which is part of the open() path in ASoC, nothing
   8 guarantees that our encoder state won't change between the time when we
   9 open the device and the time we prepare it.
  10
  11 Move the sanity checks we do in startup() to a helper and call it from
  12 prepare().
  13
  14 Fixes: 91e99e113929 ("drm/vc4: hdmi: Register HDMI codec")
  15 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  16 ---
  17  drivers/gpu/drm/vc4/vc4_hdmi.c | 35 +++++++++++++++++++++++++++-------
  18  1 file changed, 28 insertions(+), 7 deletions(-)
  19
  20 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  21 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  22 @@ -1406,20 +1406,36 @@ static inline struct vc4_hdmi *dai_to_hd
  23         return snd_soc_card_get_drvdata(card);
  24  }
  25
  26 +static bool vc4_hdmi_audio_can_stream(struct vc4_hdmi *vc4_hdmi)
  27 +{
  28 +       struct drm_encoder *encoder = &vc4_hdmi->encoder.base.base;
  29 +
  30 +       lockdep_assert_held(&vc4_hdmi->mutex);
  31 +
  32 +       /*
  33 +        * The encoder doesn't have a CRTC until the first modeset.
  34 +        */
  35 +       if (!encoder->crtc)
  36 +               return false;
  37 +
  38 +       /*
  39 +        * If the encoder is currently in DVI mode, treat the codec DAI
  40 +        * as missing.
  41 +        */
  42 +       if (!(HDMI_READ(HDMI_RAM_PACKET_CONFIG) & VC4_HDMI_RAM_PACKET_ENABLE))
  43 +               return false;
  44 +
  45 +       return true;
  46 +}
  47 +
  48  static int vc4_hdmi_audio_startup(struct device *dev, void *data)
  49  {
  50         struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
  51 -       struct drm_encoder *encoder = &vc4_hdmi->encoder.base.base;
  52         unsigned long flags;
  53
  54         mutex_lock(&vc4_hdmi->mutex);
  55
  56 -       /*
  57 -        * If the HDMI encoder hasn't probed, or the encoder is
  58 -        * currently in DVI mode, treat the codec dai as missing.
  59 -        */
  60 -       if (!encoder->crtc || !(HDMI_READ(HDMI_RAM_PACKET_CONFIG) &
  61 -                               VC4_HDMI_RAM_PACKET_ENABLE)) {
  62 +       if (!vc4_hdmi_audio_can_stream(vc4_hdmi)) {
  63                 mutex_unlock(&vc4_hdmi->mutex);
  64                 return -ENODEV;
  65         }
  66 @@ -1549,6 +1565,11 @@ static int vc4_hdmi_audio_prepare(struct
  67
  68         mutex_lock(&vc4_hdmi->mutex);
  69
  70 +       if (!vc4_hdmi_audio_can_stream(vc4_hdmi)) {
  71 +               mutex_unlock(&vc4_hdmi->mutex);
  72 +               return -EINVAL;
  73 +       }
  74 +
  75         vc4_hdmi_audio_set_mai_clock(vc4_hdmi, sample_rate);
  76
  77         spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);