| Message ID | 20220119122843.1455611-1-narmstrong@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/bridge: dw-hdmi: use safe format when first in bridge chain | expand |
On Wed, Jan 19, 2022 at 5:58 PM Neil Armstrong <narmstrong@baylibre.com> wrote: > > When the dw-hdmi bridge is in first place of the bridge chain, this > means there is no way to select an input format of the dw-hdmi HW > component. > > Since introduction of display-connector, negotiation was broken since > the dw-hdmi negotiation code only worked when the dw-hdmi bridge was > in last position of the bridge chain or behind another bridge also > supporting input & output format negotiation. > > Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") > was introduced to make negotiation work again by making display-connector > act as a pass-through concerning input & output format negotiation. > > But in the case where the dw-hdmi is single in the bridge chain, for > example on Renesas SoCs, with the display-connector bridge the dw-hdmi > is no more single, breaking output format. > > Reported-by: Biju Das <biju.das.jz@bp.renesas.com> > Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks"). > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> > --- > Changes since v1: > - Remove bad fix in dw_hdmi_bridge_atomic_get_input_bus_fmts > - Fix typos in commit message > > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > index 54d8fdad395f..97cdc61b57f6 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, > if (!output_fmts) > return NULL; > > - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ > - if (list_is_singular(&bridge->encoder->bridge_chain)) { > + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ > + if (list_is_singular(&bridge->encoder->bridge_chain) || > + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { What if we use bridge helper, drm_bridge_chain_get_first_bridge in order to find the first bridge in chain? Thanks, Jagan.
Hi, On 20/01/2022 12:14, Jagan Teki wrote: > On Wed, Jan 19, 2022 at 5:58 PM Neil Armstrong <narmstrong@baylibre.com> wrote: >> >> When the dw-hdmi bridge is in first place of the bridge chain, this >> means there is no way to select an input format of the dw-hdmi HW >> component. >> >> Since introduction of display-connector, negotiation was broken since >> the dw-hdmi negotiation code only worked when the dw-hdmi bridge was >> in last position of the bridge chain or behind another bridge also >> supporting input & output format negotiation. >> >> Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") >> was introduced to make negotiation work again by making display-connector >> act as a pass-through concerning input & output format negotiation. >> >> But in the case where the dw-hdmi is single in the bridge chain, for >> example on Renesas SoCs, with the display-connector bridge the dw-hdmi >> is no more single, breaking output format. >> >> Reported-by: Biju Das <biju.das.jz@bp.renesas.com> >> Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> >> Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> >> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks"). >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> >> --- >> Changes since v1: >> - Remove bad fix in dw_hdmi_bridge_atomic_get_input_bus_fmts >> - Fix typos in commit message >> >> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> index 54d8fdad395f..97cdc61b57f6 100644 >> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, >> if (!output_fmts) >> return NULL; >> >> - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ >> - if (list_is_singular(&bridge->encoder->bridge_chain)) { >> + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ >> + if (list_is_singular(&bridge->encoder->bridge_chain) || >> + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { > > What if we use bridge helper, drm_bridge_chain_get_first_bridge in > order to find the first bridge in chain? drm_bridge_chain_get_first_bridge() would be similar, since we already access bridge_chain in the previous check, it's simpler like that. Neil > > Thanks, > Jagan. >
Hi, On 19/01/2022 13:28, Neil Armstrong wrote: > When the dw-hdmi bridge is in first place of the bridge chain, this > means there is no way to select an input format of the dw-hdmi HW > component. > > Since introduction of display-connector, negotiation was broken since > the dw-hdmi negotiation code only worked when the dw-hdmi bridge was > in last position of the bridge chain or behind another bridge also > supporting input & output format negotiation. > > Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") > was introduced to make negotiation work again by making display-connector > act as a pass-through concerning input & output format negotiation. > > But in the case where the dw-hdmi is single in the bridge chain, for > example on Renesas SoCs, with the display-connector bridge the dw-hdmi > is no more single, breaking output format. > > Reported-by: Biju Das <biju.das.jz@bp.renesas.com> > Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks"). > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> > --- > Changes since v1: > - Remove bad fix in dw_hdmi_bridge_atomic_get_input_bus_fmts > - Fix typos in commit message > > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > index 54d8fdad395f..97cdc61b57f6 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, > if (!output_fmts) > return NULL; > > - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ > - if (list_is_singular(&bridge->encoder->bridge_chain)) { > + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ > + if (list_is_singular(&bridge->encoder->bridge_chain) || > + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { > *num_output_fmts = 1; > output_fmts[0] = MEDIA_BUS_FMT_FIXED; > Can a bridge reviewer get an eye on this ? this actually solves an issue reported on a Renesas platform. Neil
On Wed, 19 Jan 2022 at 13:28, Neil Armstrong <narmstrong@baylibre.com> wrote: > > When the dw-hdmi bridge is in first place of the bridge chain, this > means there is no way to select an input format of the dw-hdmi HW > component. > > Since introduction of display-connector, negotiation was broken since > the dw-hdmi negotiation code only worked when the dw-hdmi bridge was > in last position of the bridge chain or behind another bridge also > supporting input & output format negotiation. > > Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") I think this is the wrong hash. Is 7cd70656d128 the actual hash? > was introduced to make negotiation work again by making display-connector > act as a pass-through concerning input & output format negotiation. > > But in the case where the dw-hdmi is single in the bridge chain, for > example on Renesas SoCs, with the display-connector bridge the dw-hdmi > is no more single, breaking output format. > > Reported-by: Biju Das <biju.das.jz@bp.renesas.com> > Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks"). This hash too. > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> > --- > Changes since v1: > - Remove bad fix in dw_hdmi_bridge_atomic_get_input_bus_fmts > - Fix typos in commit message > > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > index 54d8fdad395f..97cdc61b57f6 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, > if (!output_fmts) > return NULL; > > - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ > - if (list_is_singular(&bridge->encoder->bridge_chain)) { > + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ > + if (list_is_singular(&bridge->encoder->bridge_chain) || > + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { > *num_output_fmts = 1; > output_fmts[0] = MEDIA_BUS_FMT_FIXED; > > -- > 2.25.1 > There are two checkstyle issues apart from the above mentioned hash issues, and I think we can ignore those. With the above mentioned issue fixed, feel free to add my r-b. Reviewed-by: Robert Foss <robert.foss@linaro.org>
Hi, On 04/02/2022 15:05, Robert Foss wrote: > On Wed, 19 Jan 2022 at 13:28, Neil Armstrong <narmstrong@baylibre.com> wrote: >> >> When the dw-hdmi bridge is in first place of the bridge chain, this >> means there is no way to select an input format of the dw-hdmi HW >> component. >> >> Since introduction of display-connector, negotiation was broken since >> the dw-hdmi negotiation code only worked when the dw-hdmi bridge was >> in last position of the bridge chain or behind another bridge also >> supporting input & output format negotiation. >> >> Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") > > I think this is the wrong hash. Is 7cd70656d128 the actual hash? Wow indeed, thanks for checking... > >> was introduced to make negotiation work again by making display-connector >> act as a pass-through concerning input & output format negotiation. >> >> But in the case where the dw-hdmi is single in the bridge chain, for >> example on Renesas SoCs, with the display-connector bridge the dw-hdmi >> is no more single, breaking output format. >> >> Reported-by: Biju Das <biju.das.jz@bp.renesas.com> >> Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> >> Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> >> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks"). > > This hash too. > >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> >> --- >> Changes since v1: >> - Remove bad fix in dw_hdmi_bridge_atomic_get_input_bus_fmts >> - Fix typos in commit message >> >> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> index 54d8fdad395f..97cdc61b57f6 100644 >> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c >> @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, >> if (!output_fmts) >> return NULL; >> >> - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ >> - if (list_is_singular(&bridge->encoder->bridge_chain)) { >> + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ >> + if (list_is_singular(&bridge->encoder->bridge_chain) || >> + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { >> *num_output_fmts = 1; >> output_fmts[0] = MEDIA_BUS_FMT_FIXED; >> >> -- >> 2.25.1 >> > > There are two checkstyle issues apart from the above mentioned hash > issues, and I think we can ignore those. With the above mentioned > issue fixed, feel free to add my r-b. > > Reviewed-by: Robert Foss <robert.foss@linaro.org> Thanks, I'll fix & resend with your r-b. Neil
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 54d8fdad395f..97cdc61b57f6 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, if (!output_fmts) return NULL; - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ - if (list_is_singular(&bridge->encoder->bridge_chain)) { + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ + if (list_is_singular(&bridge->encoder->bridge_chain) || + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { *num_output_fmts = 1; output_fmts[0] = MEDIA_BUS_FMT_FIXED;
When the dw-hdmi bridge is in first place of the bridge chain, this means there is no way to select an input format of the dw-hdmi HW component. Since introduction of display-connector, negotiation was broken since the dw-hdmi negotiation code only worked when the dw-hdmi bridge was in last position of the bridge chain or behind another bridge also supporting input & output format negotiation. Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") was introduced to make negotiation work again by making display-connector act as a pass-through concerning input & output format negotiation. But in the case where the dw-hdmi is single in the bridge chain, for example on Renesas SoCs, with the display-connector bridge the dw-hdmi is no more single, breaking output format. Reported-by: Biju Das <biju.das.jz@bp.renesas.com> Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks"). Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> --- Changes since v1: - Remove bad fix in dw_hdmi_bridge_atomic_get_input_bus_fmts - Fix typos in commit message drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)