git.openwrt.org Git - openwrt/staging/linusw.git/blob

   1 From d62184f6b06627b4fe922b08132e38c181d389a0 Mon Sep 17 00:00:00 2001
   2 From: Jagan Teki <jagan@amarulasolutions.com>
   3 Date: Tue, 28 Mar 2023 22:37:52 +0530
   4 Subject: [PATCH 1270/1350] drm/bridge: Document bridge init order with
   5  pre_enable_prev_first
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   9
  10 Upstream commit 113cc3ad8566e06d6c8ef4fc0075a938dedefab5
  11
  12 In order to satisfy the MIPI DSI initialization sequence the bridge
  13 init order has been altered with the help of pre_enable_prev_first
  14 in pre_enable and post_disable bridge operations.
  15
  16 Document the affected bridge init order with an example on the
  17 bridge operations helpers.
  18
  19 Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
  20 Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  21 Signed-off-by: Robert Foss <rfoss@kernel.org>
  22 Link: https://patchwork.freedesktop.org/patch/msgid/20230328170752.1102347-2-jagan@amarulasolutions.com
  23 ---
  24  drivers/gpu/drm/drm_bridge.c | 14 ++++++++++++++
  25  1 file changed, 14 insertions(+)
  26
  27 --- a/drivers/gpu/drm/drm_bridge.c
  28 +++ b/drivers/gpu/drm/drm_bridge.c
  29 @@ -657,6 +657,13 @@ static void drm_atomic_bridge_call_post_
  30   * bridge will be called before the previous one to reverse the @pre_enable
  31   * calling direction.
  32   *
  33 + * Example:
  34 + * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E
  35 + *
  36 + * With pre_enable_prev_first flag enable in Bridge B, D, E then the resulting
  37 + * @post_disable order would be,
  38 + * Bridge B, Bridge A, Bridge E, Bridge D, Bridge C.
  39 + *
  40   * Note: the bridge passed should be the one closest to the encoder
  41   */
  42  void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
  43 @@ -753,6 +760,13 @@ static void drm_atomic_bridge_call_pre_e
  44   * If a bridge sets @pre_enable_prev_first, then the pre_enable for the
  45   * prev bridge will be called before pre_enable of this bridge.
  46   *
  47 + * Example:
  48 + * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E
  49 + *
  50 + * With pre_enable_prev_first flag enable in Bridge B, D, E then the resulting
  51 + * @pre_enable order would be,
  52 + * Bridge C, Bridge D, Bridge E, Bridge A, Bridge B.
  53 + *
  54   * Note: the bridge passed should be the one closest to the encoder
  55   */
  56  void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,