On Sun, 24 Nov 2019 12:33:35 +0200
Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> Hi Boris,
>
> Thank you for the patch.
>
> On Wed, Oct 23, 2019 at 05:44:56PM +0200, Boris Brezillon wrote:
> > And use it in drivers accessing the bridge->next field directly.
> > This is part of our attempt to make the bridge chain a double-linked list
> > based on the generic list helpers.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> > ---
> > Changes in v3:
> > * Inline drm_bridge_chain_get_next_bridge() (Suggested by Laurent)
> >
> > Changes in v2:
> > * Kill the last/first helpers (they're not really needed)
> > * Drop the !bridge || !bridge->encoder test
> > ---
> > drivers/gpu/drm/exynos/exynos_drm_dsi.c | 3 ++-
> > drivers/gpu/drm/mediatek/mtk_hdmi.c | 6 ++++--
> > drivers/gpu/drm/omapdrm/omap_drv.c | 4 ++--
> > drivers/gpu/drm/omapdrm/omap_encoder.c | 3 ++-
> > drivers/gpu/drm/vc4/vc4_dsi.c | 4 +++-
> > include/drm/drm_bridge.h | 13 +++++++++++++
> > 6 files changed, 26 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> > index 3915f50b005e..005c67894b78 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> > @@ -1593,9 +1593,10 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
> > struct mipi_dsi_device *device)
> > {
> > struct exynos_dsi *dsi = host_to_dsi(host);
> > - struct drm_bridge *out_bridge = dsi->bridge.next;
> > struct drm_device *drm = dsi->encoder.dev;
> > + struct drm_bridge *out_bridge;
> >
> > + out_bridge = drm_bridge_chain_get_next_bridge(&dsi->bridge);
>
> You may want to store this in the exynos_dsi structure in the previous
> patch where you rework this driver.
Do we really need to store it there, since we already have a simple way
to retrieve the next bridge in the chain?
>
> > if (dsi->panel) {
> > mutex_lock(&drm->mode_config.mutex);
> > exynos_dsi_disable(&dsi->bridge);
> > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> > index ea68b5adccbe..cfaa5aab8876 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> > @@ -1238,16 +1238,18 @@ static int mtk_hdmi_conn_mode_valid(struct drm_connector *conn,
> > struct drm_display_mode *mode)
> > {
> > struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
> > + struct drm_bridge *next_bridge;
> >
> > dev_dbg(hdmi->dev, "xres=%d, yres=%d, refresh=%d, intl=%d clock=%d\n",
> > mode->hdisplay, mode->vdisplay, mode->vrefresh,
> > !!(mode->flags & DRM_MODE_FLAG_INTERLACE), mode->clock * 1000);
> >
> > - if (hdmi->bridge.next) {
> > + next_bridge = drm_bridge_chain_get_next_bridge(&hdmi->bridge);
> > + if (next_bridge) {
> > struct drm_display_mode adjusted_mode;
> >
> > drm_mode_copy(&adjusted_mode, mode);
> > - if (!drm_bridge_chain_mode_fixup(hdmi->bridge.next, mode,
> > + if (!drm_bridge_chain_mode_fixup(next_bridge, mode,
> > &adjusted_mode))
> > return MODE_BAD;
> > }
> > diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
> > index b3e22c890c51..865164fe28dc 100644
> > --- a/drivers/gpu/drm/omapdrm/omap_drv.c
> > +++ b/drivers/gpu/drm/omapdrm/omap_drv.c
> > @@ -217,8 +217,8 @@ static int omap_display_id(struct omap_dss_device *output)
> > } else if (output->bridge) {
> > struct drm_bridge *bridge = output->bridge;
> >
> > - while (bridge->next)
> > - bridge = bridge->next;
> > + while (drm_bridge_chain_get_next_bridge(bridge))
> > + bridge = drm_bridge_chain_get_next_bridge(bridge);
> >
> > node = bridge->of_node;
> > } else if (output->panel) {
> > diff --git a/drivers/gpu/drm/omapdrm/omap_encoder.c b/drivers/gpu/drm/omapdrm/omap_encoder.c
> > index 24bbe9f2a32e..8ca54081997e 100644
> > --- a/drivers/gpu/drm/omapdrm/omap_encoder.c
> > +++ b/drivers/gpu/drm/omapdrm/omap_encoder.c
> > @@ -126,7 +126,8 @@ static void omap_encoder_mode_set(struct drm_encoder *encoder,
> > for (dssdev = output; dssdev; dssdev = dssdev->next)
> > omap_encoder_update_videomode_flags(&vm, dssdev->bus_flags);
> >
> > - for (bridge = output->bridge; bridge; bridge = bridge->next) {
> > + for (bridge = output->bridge; bridge;
> > + bridge = drm_bridge_chain_get_next_bridge(bridge)) {
>
> A for_each_bridge() macro would be nice (in a separate patch). It could
> be used in omap_drv.c above too.
It's coming later in the series (patch 8).
>
> > if (!bridge->timings)
> > continue;
> >
> > diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> > index 49f8a313e759..49c47185aff0 100644
> > --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> > +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> > @@ -1644,8 +1644,10 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master,
> > struct drm_device *drm = dev_get_drvdata(master);
> > struct vc4_dev *vc4 = to_vc4_dev(drm);
> > struct vc4_dsi *dsi = dev_get_drvdata(dev);
> > + struct drm_bridge *bridge;
> >
> > - if (dsi->bridge.next)
> > + bridge = drm_bridge_chain_get_next_bridge(&dsi->bridge);
> > + if (bridge)
> > pm_runtime_disable(dev);
> >
> > vc4_dsi_encoder_destroy(dsi->encoder);
> > diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> > index 726435baf4ad..8aeba83fcf31 100644
> > --- a/include/drm/drm_bridge.h
> > +++ b/include/drm/drm_bridge.h
> > @@ -409,6 +409,19 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np);
> > int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
> > struct drm_bridge *previous);
> >
> > +/**
> > + * drm_bridge_chain_get_next_bridge() - Get the next bridge in the chain
> > + * @bridge: bridge object
> > + *
> > + * RETURNS:
> > + * the next bridge in the chain, or NULL if @bridge is the last.
>
> Maybe "the next bridge in the chain after @bridge, ..." ?
Agreed.
>
> > + */
> > +static inline struct drm_bridge *
> > +drm_bridge_chain_get_next_bridge(struct drm_bridge *bridge)
>
> Technically speaking this doesn't operate on a chain but on a bridge, so
> I'd name is drm_bridge_get_next_bridge(). I will not insist to the way
> of nacking the series for this, so with the rename, but also without,
You're absolutely right, I'll rename the function as suggested.
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> > +{
> > + return bridge->next;
> > +}
> > +
> > bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
> > const struct drm_display_mode *mode,
> > struct drm_display_mode *adjusted_mode);
>
