target/linux/bcm27xx/patches-5.4/950-0860-drm-vc4-FKMS-Block-modes-with-odd-horizontal-timing-.patch

   1 From aa791f2cb6777e8ca99102009b631afdeea1c59d Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Fri, 3 Jul 2020 16:06:55 +0100
   4 Subject: [PATCH] drm/vc4: FKMS Block modes with odd horizontal
   5  timing values on Pi4
   6
   7 Pi4 HDMI pipeline is 2 pixels/clock and can not produce timings
   8 that have odd values for active pixels, front porch, sync width,
   9 or back porch.
  10 Detect these modes and block them within fkms.
  11
  12 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  13 ---
  14  drivers/gpu/drm/vc4/vc4_firmware_kms.c | 21 +++++++++++++++++++++
  15  1 file changed, 21 insertions(+)
  16
  17 --- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
  18 +++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
  19 @@ -44,6 +44,7 @@ struct get_display_cfg {
  20
  21  struct vc4_fkms {
  22         struct get_display_cfg cfg;
  23 +       bool bcm2711;
  24  };
  25
  26  #define PLANES_PER_CRTC                3
  27 @@ -1097,6 +1098,17 @@ vc4_crtc_mode_valid(struct drm_crtc *crt
  28                 break;
  29         }
  30
  31 +       /* Pi4 can't generate odd horizontal timings on HDMI, so reject modes
  32 +        * that would set them.
  33 +        */
  34 +       if (fkms->bcm2711 &&
  35 +           (vc4_crtc->display_number == 2 || vc4_crtc->display_number == 7) &&
  36 +           ((mode->hdisplay |                          /* active */
  37 +             (mode->hsync_start - mode->hdisplay) |    /* front porch */
  38 +             (mode->hsync_end - mode->hsync_start) |   /* sync pulse */
  39 +             (mode->htotal - mode->hsync_end)) & 1))   /* back porch */
  40 +               return MODE_H_ILLEGAL;
  41 +
  42         return MODE_OK;
  43  }
  44
  45 @@ -1282,6 +1294,8 @@ static const struct drm_crtc_helper_func
  46
  47  static const struct of_device_id vc4_firmware_kms_dt_match[] = {
  48         { .compatible = "raspberrypi,rpi-firmware-kms" },
  49 +       { .compatible = "raspberrypi,rpi-firmware-kms-2711",
  50 +         .data = (void *)1 },
  51         {}
  52  };
  53
  54 @@ -1815,6 +1829,7 @@ static int vc4_fkms_bind(struct device *
  55         struct drm_device *drm = dev_get_drvdata(master);
  56         struct vc4_dev *vc4 = to_vc4_dev(drm);
  57         struct device_node *firmware_node;
  58 +       const struct of_device_id *match;
  59         struct vc4_crtc **crtc_list;
  60         u32 num_displays, display_num;
  61         struct vc4_fkms *fkms;
  62 @@ -1827,6 +1842,12 @@ static int vc4_fkms_bind(struct device *
  63         if (!fkms)
  64                 return -ENOMEM;
  65
  66 +       match = of_match_device(vc4_firmware_kms_dt_match, dev);
  67 +       if (!match)
  68 +               return -ENODEV;
  69 +       if (match->data)
  70 +               fkms->bcm2711 = true;
  71 +
  72         /* firmware kms doesn't have precise a scanoutpos implementation, so
  73          * we can't do the precise vblank timestamp mode.
  74          */