| Message ID | 20220117141750.1182223-1-narmstrong@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: dw-hdmi: use safe format when first in bridge chain | expand |
Hi Neil, Thanks for the patch > Subject: [PATCH] drm/bridge: dw-hdmi: use safe format when first in bridge > chain > > When the dw-hdmi bridge is in first place of the bridge chain, this means > there is now way to select an input format of the dw-hdmi HW component. > > Since introduction of display-connector, negociation was broken since the > dw-hdmi negociation 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 negociation. > > Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts > callbacks") was introduced to make negociation work again by making > display-connector act as a pass-through concerning input & output format > negociation. > > But in the case were the dw-hdmi was single in the bridge chain, for > example on Renesas SoCs, with the disply-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> > --- > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++++-- > 1 file changed, 7 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..9f2e1cac0ae2 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; > > @@ -2673,6 +2674,10 @@ static u32 > *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, > if (!input_fmts) > return NULL; > > + /* If dw-hdmi is the first bridge fall-back to safe output format */ > + if (list_is_first(&bridge->chain_node, &bridge->encoder- > >bridge_chain)) > + output_fmt = MEDIA_BUS_FMT_FIXED; > + Based on my debugging, this looks redundant, as get_output_bus_fmts already sets output_fmt = MEDIA_BUS_FMT_FIXED, And *num_output_fmts = 1, so the function parameter output_fmt in input_bus_fmts will have MEDIA_BUS_FMT_FIXED And no need to override output_fmt value. I may be wrong here. Regards, Biju > switch (output_fmt) { > /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ > case MEDIA_BUS_FMT_FIXED: > -- > 2.25.1
On 17/01/2022 15:27, Biju Das wrote: > Hi Neil, > > Thanks for the patch > >> Subject: [PATCH] drm/bridge: dw-hdmi: use safe format when first in bridge >> chain >> >> When the dw-hdmi bridge is in first place of the bridge chain, this means >> there is now way to select an input format of the dw-hdmi HW component. >> >> Since introduction of display-connector, negociation was broken since the >> dw-hdmi negociation 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 negociation. >> >> Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts >> callbacks") was introduced to make negociation work again by making >> display-connector act as a pass-through concerning input & output format >> negociation. >> >> But in the case were the dw-hdmi was single in the bridge chain, for >> example on Renesas SoCs, with the disply-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> >> --- >> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++++-- >> 1 file changed, 7 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..9f2e1cac0ae2 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; >> >> @@ -2673,6 +2674,10 @@ static u32 >> *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, >> if (!input_fmts) >> return NULL; >> >> + /* If dw-hdmi is the first bridge fall-back to safe output format */ >> + if (list_is_first(&bridge->chain_node, &bridge->encoder- >>> bridge_chain)) >> + output_fmt = MEDIA_BUS_FMT_FIXED; >> + > > Based on my debugging, this looks redundant, as get_output_bus_fmts already sets output_fmt = MEDIA_BUS_FMT_FIXED, > And *num_output_fmts = 1, so the function parameter output_fmt in input_bus_fmts will have MEDIA_BUS_FMT_FIXED > And no need to override output_fmt value. I may be wrong here. You're right, I added this in case another bridge than display-connector is used, but in fact it should instead check if first bridge of the chain and output_fmt == MEDIA_BUS_FMT_RGB888_1X24 || output_fmt == MEDIA_BUS_FMT_FIXED otherwise return an error. I'll send it separately since it's out of the scope of the issue fixed. Neil > > Regards, > Biju > >> switch (output_fmt) { >> /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ >> case MEDIA_BUS_FMT_FIXED: >> -- >> 2.25.1 >
Hi Neil Sorry, just some trivial spelling fixes. On Mon, 2022-01-17 at 15:17 +0100, Neil Armstrong wrote: > When the dw-hdmi bridge is in first place of the bridge chain, this > means there is now way no way > to select an input format of the dw-hdmi HW > component. > > Since introduction of display-connector, negociation :%s/negociation/negotiation/g > was broken since > the dw-hdmi negociation 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 negociation. > > Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") > was introduced to make negociation work again by making display-connector > act as a pass-through concerning input & output format negociation. > > But in the case were where > the dw-hdmi was single in the bridge chain, for > example on Renesas SoCs, with the disply-connector 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> > --- > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++++-- > 1 file changed, 7 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..9f2e1cac0ae2 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; > > @@ -2673,6 +2674,10 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, > if (!input_fmts) > return NULL; > > + /* If dw-hdmi is the first bridge fall-back to safe output format */ > + if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) > + output_fmt = MEDIA_BUS_FMT_FIXED; > + > switch (output_fmt) { > /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ > case MEDIA_BUS_FMT_FIXED: Cheers Marcel
Hi, On 17/01/2022 17:53, Marcel Ziswiler wrote: > Hi Neil > > Sorry, just some trivial spelling fixes. > > On Mon, 2022-01-17 at 15:17 +0100, Neil Armstrong wrote: >> When the dw-hdmi bridge is in first place of the bridge chain, this >> means there is now way > > no way > >> to select an input format of the dw-hdmi HW >> component. >> >> Since introduction of display-connector, negociation > > :%s/negociation/negotiation/g > >> was broken since >> the dw-hdmi negociation 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 negociation. >> >> Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") >> was introduced to make negociation work again by making display-connector >> act as a pass-through concerning input & output format negociation. >> >> But in the case were > > where > >> the dw-hdmi was single in the bridge chain, for >> example on Renesas SoCs, with the disply-connector > > 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> >> --- >> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++++-- >> 1 file changed, 7 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..9f2e1cac0ae2 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; >> >> @@ -2673,6 +2674,10 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, >> if (!input_fmts) >> return NULL; >> >> + /* If dw-hdmi is the first bridge fall-back to safe output format */ >> + if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) >> + output_fmt = MEDIA_BUS_FMT_FIXED; >> + >> switch (output_fmt) { >> /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ >> case MEDIA_BUS_FMT_FIXED: > > Cheers > > Marcel > Thanks for the spelling fixes, Neil
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 54d8fdad395f..9f2e1cac0ae2 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; @@ -2673,6 +2674,10 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, if (!input_fmts) return NULL; + /* If dw-hdmi is the first bridge fall-back to safe output format */ + if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) + output_fmt = MEDIA_BUS_FMT_FIXED; + switch (output_fmt) { /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ case MEDIA_BUS_FMT_FIXED:
When the dw-hdmi bridge is in first place of the bridge chain, this means there is now way to select an input format of the dw-hdmi HW component. Since introduction of display-connector, negociation was broken since the dw-hdmi negociation 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 negociation. Commit 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks") was introduced to make negociation work again by making display-connector act as a pass-through concerning input & output format negociation. But in the case were the dw-hdmi was single in the bridge chain, for example on Renesas SoCs, with the disply-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> --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)