diff mbox series

[v3,RESEND,3/9] drm/bridge: synopsys: dw-mipi-dsi: Force input bus flags

Message ID 20230821034008.3876938-4-victor.liu@nxp.com (mailing list archive)
State New, archived
Headers show
Series drm/bridge: imx: Add i.MX93 MIPI DSI support | expand

Commit Message

Liu Ying Aug. 21, 2023, 3:40 a.m. UTC 
The DATAEN_ACTIVE_LOW bit in DSI_DPI_CFG_POL register is set to zero,
so set the DRM_BUS_FLAG_DE_HIGH flag in input_bus_cfg.flags.  It appears
that the DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE flag also makes sense, so
set it in input_bus_cfg.flags too.  With this patch, the flags set by
drm_atomic_bridge_propagate_bus_flags() are overridden (see comment in
that function) in case any downstream bridges propagates invalid flags
to this bridge.  A real problematic case is to connect a RM67191 MIPI
DSI panel whose driver sets DRM_BUS_FLAG_DE_LOW and
DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE bus flags.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v1->v3:
* No change.

 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Robert Foss Oct. 16, 2023, 9:33 a.m. UTC | #1 
On Mon, Aug 21, 2023 at 5:37 AM Liu Ying <victor.liu@nxp.com> wrote:
>
> The DATAEN_ACTIVE_LOW bit in DSI_DPI_CFG_POL register is set to zero,
> so set the DRM_BUS_FLAG_DE_HIGH flag in input_bus_cfg.flags.  It appears
> that the DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE flag also makes sense, so
> set it in input_bus_cfg.flags too.  With this patch, the flags set by
> drm_atomic_bridge_propagate_bus_flags() are overridden (see comment in
> that function) in case any downstream bridges propagates invalid flags
> to this bridge.  A real problematic case is to connect a RM67191 MIPI
> DSI panel whose driver sets DRM_BUS_FLAG_DE_LOW and
> DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE bus flags.
>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v1->v3:
> * No change.
>
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 945d46a76995..ed9288a9c444 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -23,6 +23,7 @@
>  #include <drm/bridge/dw_mipi_dsi.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> +#include <drm/drm_connector.h>
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_mipi_dsi.h>
>  #include <drm/drm_modes.h>
> @@ -567,6 +568,17 @@ dw_mipi_dsi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
>         return input_fmts;
>  }
>
> +static int dw_mipi_dsi_bridge_atomic_check(struct drm_bridge *bridge,
> +                                          struct drm_bridge_state *bridge_state,
> +                                          struct drm_crtc_state *crtc_state,
> +                                          struct drm_connector_state *conn_state)
> +{
> +       bridge_state->input_bus_cfg.flags =
> +               DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
> +
> +       return 0;
> +}
> +
>  static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
>  {
>         u32 val;
> @@ -1036,6 +1048,7 @@ static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
>         .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
>         .atomic_destroy_state   = drm_atomic_helper_bridge_destroy_state,
>         .atomic_get_input_bus_fmts = dw_mipi_dsi_bridge_atomic_get_input_bus_fmts,
> +       .atomic_check           = dw_mipi_dsi_bridge_atomic_check,
>         .atomic_reset           = drm_atomic_helper_bridge_reset,
>         .atomic_pre_enable      = dw_mipi_dsi_bridge_atomic_pre_enable,
>         .atomic_enable          = dw_mipi_dsi_bridge_atomic_enable,
> --
> 2.37.1
>

Reviewed-by: Robert Foss <rfoss@kernel.org>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 945d46a76995..ed9288a9c444 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -23,6 +23,7 @@ 
 #include <drm/bridge/dw_mipi_dsi.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_connector.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_modes.h>
@@ -567,6 +568,17 @@  dw_mipi_dsi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
 	return input_fmts;
 }
 
+static int dw_mipi_dsi_bridge_atomic_check(struct drm_bridge *bridge,
+					   struct drm_bridge_state *bridge_state,
+					   struct drm_crtc_state *crtc_state,
+					   struct drm_connector_state *conn_state)
+{
+	bridge_state->input_bus_cfg.flags =
+		DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
+
+	return 0;
+}
+
 static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
 {
 	u32 val;
@@ -1036,6 +1048,7 @@  static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
 	.atomic_get_input_bus_fmts = dw_mipi_dsi_bridge_atomic_get_input_bus_fmts,
+	.atomic_check		= dw_mipi_dsi_bridge_atomic_check,
 	.atomic_reset		= drm_atomic_helper_bridge_reset,
 	.atomic_pre_enable	= dw_mipi_dsi_bridge_atomic_pre_enable,
 	.atomic_enable		= dw_mipi_dsi_bridge_atomic_enable,