target/linux/bcm27xx/patches-5.10/950-0683-drm-vc4-Simplify-a-bit-the-global-atomic_check.patch

   1 From d88f88dfdce0c6911802cb9a0da0c43ade854183 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Fri, 4 Dec 2020 16:11:34 +0100
   4 Subject: [PATCH] drm/vc4: Simplify a bit the global atomic_check
   5
   6 When we can't allocate a new channel, we can simply return instead of
   7 having to handle both cases, and that simplifies a bit the code.
   8
   9 Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
  10 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  11 ---
  12  drivers/gpu/drm/vc4/vc4_kms.c | 13 ++++++-------
  13  1 file changed, 6 insertions(+), 7 deletions(-)
  14
  15 --- a/drivers/gpu/drm/vc4/vc4_kms.c
  16 +++ b/drivers/gpu/drm/vc4/vc4_kms.c
  17 @@ -793,6 +793,7 @@ static int vc4_pv_muxing_atomic_check(st
  18                         to_vc4_crtc_state(new_crtc_state);
  19                 struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
  20                 unsigned int matching_channels;
  21 +               unsigned int channel;
  22
  23                 if (vc4->firmware_kms)
  24                         continue;
  25 @@ -836,14 +837,12 @@ static int vc4_pv_muxing_atomic_check(st
  26                  * but it works so far.
  27                  */
  28                 matching_channels = hvs_new_state->unassigned_channels & vc4_crtc->data->hvs_available_channels;
  29 -               if (matching_channels) {
  30 -                       unsigned int channel = ffs(matching_channels) - 1;
  31 -
  32 -                       new_vc4_crtc_state->assigned_channel = channel;
  33 -                       hvs_new_state->unassigned_channels &= ~BIT(channel);
  34 -               } else {
  35 +               if (!matching_channels)
  36                         return -EINVAL;
  37 -               }
  38 +
  39 +               channel = ffs(matching_channels) - 1;
  40 +               new_vc4_crtc_state->assigned_channel = channel;
  41 +               hvs_new_state->unassigned_channels &= ~BIT(channel);
  42         }
  43
  44         return 0;