target/linux/bcm27xx/patches-5.10/950-0669-drm-vc4-hdmi-Make-sure-the-device-is-powered-with-CE.patch

   1 From ea4d08578d2e002ce01a2f6913c78fbff8195985 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Tue, 29 Jun 2021 11:41:57 +0200
   4 Subject: [PATCH] drm/vc4: hdmi: Make sure the device is powered with
   5  CEC
   6
   7 Similarly to what we encountered with the detect hook with DRM, nothing
   8 actually prevents any of the CEC callback from being run while the HDMI
   9 output is disabled.
  10
  11 However, this is an issue since any register access to the controller
  12 when it's powered down will result in a silent hang.
  13
  14 Let's make sure we run the runtime_pm hooks when the CEC adapter is
  15 opened and closed by the userspace to avoid that issue.
  16
  17 Fixes: 15b4511a4af6 ("drm/vc4: add HDMI CEC support")
  18 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  19 ---
  20  drivers/gpu/drm/vc4/vc4_hdmi.c | 7 +++++++
  21  1 file changed, 7 insertions(+)
  22
  23 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  24 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  25 @@ -1761,6 +1761,11 @@ static int vc4_hdmi_cec_enable(struct ce
  26         /* clock period in microseconds */
  27         const u32 usecs = 1000000 / CEC_CLOCK_FREQ;
  28         u32 val = HDMI_READ(HDMI_CEC_CNTRL_5);
  29 +       int ret;
  30 +
  31 +       ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
  32 +       if (ret)
  33 +               return ret;
  34
  35         val &= ~(VC4_HDMI_CEC_TX_SW_RESET | VC4_HDMI_CEC_RX_SW_RESET |
  36                  VC4_HDMI_CEC_CNT_TO_4700_US_MASK |
  37 @@ -1804,6 +1809,8 @@ static int vc4_hdmi_cec_disable(struct c
  38         HDMI_WRITE(HDMI_CEC_CNTRL_5, HDMI_READ(HDMI_CEC_CNTRL_5) |
  39                    VC4_HDMI_CEC_TX_SW_RESET | VC4_HDMI_CEC_RX_SW_RESET);
  40
  41 +       pm_runtime_put(&vc4_hdmi->pdev->dev);
  42 +
  43         return 0;
  44  }
  45