Re: [PATCH 00/27] Converter R-Car DU to the DRM bridge connector helper

[Sam Ravnborg <sam@ravnborg.org>]

Hi Liu,

thanks for the notice.

Laurent, I trust you will take a look and resolve this.

	Sam

On Thu, Jun 25, 2020 at 04:48:01PM +0800, Liu Ying wrote:
> Hi Sam,
> 
> On Tue, 2020-06-23 at 20:55 +0200, Sam Ravnborg wrote:
> > Hi Laurent.
> > 
> > On Tue, May 26, 2020 at 04:14:38AM +0300, Laurent Pinchart wrote:
> > > Hello,
> > > 
> > > This patch series converts the R-Car DU driver to use the DRM
> > > bridge
> > > connector helper drm_bridge_connector_init().
> > > 
> > > The bulk of the series is conversion of the adv7511, simple-bridge,
> > > rcar-lbds and dw-hdmi drivers to make connector creation optional
> > > (through the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag).
> > > 
> > > The series starts with the adv7511 driver, previously posted as
> > > "[PATCH
> > > 0/4] drm: bridge: adv7511: Enable usage with DRM bridge connector
> > > helper" ([1]). Patches 01/27 to 04/27 incorporate all the received
> > > review comments.
> > > 
> > > The next three patches address the simple-bridge driver, previously
> > > posted as "[PATCH 0/2] drm: bridge: simple-bridge: Enable usage
> > > with DRM
> > > bridge connector helper". Patch 05/27 is an additional fix that
> > > stems
> > > from the review, and patches 06/27 and 07/27 incorporate all the
> > > received review comments.
> > > 
> > > Patch 08/27 is a new patch that addresses the rcar-lvds driver.
> > > Instead
> > > of implementing direct support for DRM_BRIDGE_ATTACH_NO_CONNECTOR,
> > > it
> > > simply removes code that shouldn't have been in the driver in the
> > > first
> > > place by switching to the panel bridge helper.
> > > 
> > > Patches 09/27 to 22/27 then address the dw-hdmi driver. That's a
> > > more
> > > sizeable rework, due to the fact that the driver implements a mid-
> > > layer
> > > for platform-specific glue, with the internal drm_connector being
> > > used
> > > throughout the whole code. There's no rocket science there, but
> > > patch
> > > 10/27 should be noted for adding a new argument to the
> > > drm_bridge_funcs.mode_valid() function. Please see individual
> > > patches
> > > for details.
> > > 
> > > Patch 23/27 adds support to the dw-hdmi driver to attach to a
> > > downstream
> > > bridge if one is specified in DT. As the DT port number
> > > corresponding to
> > > the video output differs between platforms that integrate the dw-
> > > hdmi
> > > (some of them even don't have a video output port, which should
> > > probably
> > > be fixed, but that's out of scope for this series), the port number
> > > has
> > > to be specified by the platform glue layer. Patch 24/27 does so for
> > > the
> > > R-Car dw-hdmi driver.
> > > 
> > > Patch 25/27 is a drive-by fix for an error path issue in the rcar-
> > > du
> > > driver. Patch 26/27 finally makes use of the
> > > drm_bridge_connector_init()
> > > helper.
> > > 
> > > Unfortunately, this breaks the VGA output on R-Car Gen3 platforms.
> > > On
> > > those platforms, the VGA DDC lines are not connected, and there is
> > > no
> > > mean for software to detect the VGA output connection status. When
> > > the
> > > simple-bridge driver creates a connector, it automatically adds
> > > default
> > > modes when no DDC is available. This behavious is also present int
> > > the
> > > DRM probe helper drm_helper_probe_single_connector_modes(), but
> > > only
> > > when the connector status is connector_status_connected. As the
> > > driver
> > > (rightfully) reports connector_status_unconnected, no modes are
> > > added.
> > > Patch 27/27 fixes this issue by extending addition of default modes
> > > in
> > > drm_helper_probe_single_connector_modes() when the output status is
> > > unknown. An alternative approach would be to implement this
> > > behaviour in
> > > the bridge connector helper (drm_bridge_connector.c).
> > > 
> > > All the modified drivers have been compile-tested, and the series
> > > has
> > > been tested on a Renesas R-Car Salvator-XS board with the VGA, HDMI
> > > and
> > > LVDS outputs.
> > > 
> > > [1] 
> > > https://lore.kernel.org/dri-devel/20200409004610.12346-1-laurent.pinchart+renesas@ideasonboard.com/
> > > [2] 
> > > https://lore.kernel.org/dri-devel/20200409003636.11792-1-laurent.pinchart+renesas@ideasonboard.com/
> > 
> > As we briefly discussed on IRC the first 21 patches are now applied
> > to
> > drm-misc-next.
> 
> I see patch '[22/27] drm: bridge: dw-hdmi: Make connector creation
> optional' is applied to drm-misc-next.
> That patch would introduce an uninitialized mutex accessing issue as I
> mentioned in the patch[1]. And, the patch intends to fix the issue in
> the first place.
> 
> [1] https://patchwork.freedesktop.org/patch/370560/
> 
> 
> Regards,
> Liu Ying
> 
> > The rcar-du specific patches was left out and the last patch was
> > likewise not applied in this round- mostly because it was the coming
> > after several rcar-du patches and I was not sure if there was some
> > dependencies to consider.
> > 
> > With this set in we have more examples in the tree how to do proper
> > bridges which is good.
> > 
> > While applying the new r-bs was ofc added.
> > 
> > 	Sam
> > 
> > > 
> > > Laurent Pinchart (27):
> > >   drm: bridge: adv7511: Split EDID read to a separate function
> > >   drm: bridge: adv7511: Split connector creation to a separate
> > > function
> > >   drm: bridge: adv7511: Implement bridge connector operations
> > >   drm: bridge: adv7511: Make connector creation optional
> > >   drm: bridge: Return NULL on error from drm_bridge_get_edid()
> > >   drm: bridge: simple-bridge: Delegate operations to next bridge
> > >   drm: bridge: simple-bridge: Make connector creation optional
> > >   drm: rcar-du: lvds: Convert to DRM panel bridge helper
> > >   drm: edid: Constify connector argument to infoframe functions
> > >   drm: bridge: Pass drm_display_info to drm_bridge_funcs
> > > .mode_valid()
> > >   drm: bridge: dw-hdmi: Pass private data pointer to .mode_valid()
> > >   drm: bridge: dw-hdmi: Pass private data pointer to
> > > .configure_phy()
> > >   drm: bridge: dw-hdmi: Remove unused field from dw_hdmi_plat_data
> > >   drm: meson: dw-hdmi: Use dw_hdmi context to replace hack
> > >   drm: bridge: dw-hdmi: Pass drm_display_info to .mode_valid()
> > >   drm: bridge: dw-hdmi: Constify mode argument to dw_hdmi_phy_ops
> > >     .init()
> > >   drm: bridge: dw-hdmi: Constify mode argument to internal
> > > functions
> > >   drm: bridge: dw-hdmi: Pass drm_display_info to
> > > dw_hdmi_support_scdc()
> > >   drm: bridge: dw-hdmi: Split connector creation to a separate
> > > function
> > >   drm: bridge: dw-hdmi: Store current connector in struct dw_hdmi
> > >   drm: bridge: dw-hdmi: Pass drm_connector to internal functions as
> > >     needed
> > >   drm: bridge: dw-hdmi: Make connector creation optional
> > >   drm: bridge: dw-hdmi: Attach to next bridge if available
> > >   drm: rcar-du: dw-hdmi: Set output port number
> > >   drm: rcar-du: Fix error handling in rcar_du_encoder_init()
> > >   drm: rcar-du: Use drm_bridge_connector_init() helper
> > >   drm: Add default modes for connectors in unknown state
> > > 
> > >  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c  | 159 +++++---
> > >  .../drm/bridge/analogix/analogix-anx6345.c    |   1 +
> > >  .../drm/bridge/analogix/analogix-anx78xx.c    |   1 +
> > >  drivers/gpu/drm/bridge/cdns-dsi.c             |   1 +
> > >  drivers/gpu/drm/bridge/chrontel-ch7033.c      |   1 +
> > >  drivers/gpu/drm/bridge/nwl-dsi.c              |   1 +
> > >  drivers/gpu/drm/bridge/sii9234.c              |   1 +
> > >  drivers/gpu/drm/bridge/sil-sii8620.c          |   1 +
> > >  drivers/gpu/drm/bridge/simple-bridge.c        | 113 +++---
> > >  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     | 357 ++++++++++++
> > > ------
> > >  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c |   1 +
> > >  drivers/gpu/drm/bridge/tc358767.c             |   1 +
> > >  drivers/gpu/drm/bridge/tc358768.c             |   1 +
> > >  drivers/gpu/drm/bridge/thc63lvd1024.c         |   1 +
> > >  drivers/gpu/drm/bridge/ti-tfp410.c            |  11 +-
> > >  drivers/gpu/drm/drm_atomic_helper.c           |   3 +-
> > >  drivers/gpu/drm/drm_bridge.c                  |  10 +-
> > >  drivers/gpu/drm/drm_edid.c                    |  12 +-
> > >  drivers/gpu/drm/drm_probe_helper.c            |   7 +-
> > >  drivers/gpu/drm/i2c/tda998x_drv.c             |   1 +
> > >  drivers/gpu/drm/imx/dw_hdmi-imx.c             |   6 +-
> > >  drivers/gpu/drm/meson/meson_dw_hdmi.c         |  34 +-
> > >  drivers/gpu/drm/omapdrm/dss/dpi.c             |   1 +
> > >  drivers/gpu/drm/omapdrm/dss/sdi.c             |   1 +
> > >  drivers/gpu/drm/omapdrm/dss/venc.c            |   1 +
> > >  drivers/gpu/drm/rcar-du/rcar_du_encoder.c     |  26 +-
> > >  drivers/gpu/drm/rcar-du/rcar_dw_hdmi.c        |   7 +-
> > >  drivers/gpu/drm/rcar-du/rcar_lvds.c           | 124 +-----
> > >  drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c   |   6 +-
> > >  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c         |   6 +-
> > >  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h         |   3 +-
> > >  drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c        |   3 +-
> > >  include/drm/bridge/dw_hdmi.h                  |  28 +-
> > >  include/drm/drm_bridge.h                      |   3 +
> > >  include/drm/drm_edid.h                        |   6 +-
> > >  include/drm/drm_modeset_helper_vtables.h      |   8 +-
> > >  36 files changed, 541 insertions(+), 406 deletions(-)
> > > 
> > > -- 
> > > Regards,
> > > 
> > > Laurent Pinchart
> > > 
> > > _______________________________________________
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> > 
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