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 <[email protected]>
Bisected-by: Kieran Bingham <[email protected]>
Tested-by: Kieran Bingham <[email protected]>
Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks").
Signed-off-by: Neil Armstrong <[email protected]>
---
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
On Wed, Jan 19, 2022 at 5:58 PM Neil Armstrong <[email protected]> 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 <[email protected]>
> Bisected-by: Kieran Bingham <[email protected]>
> Tested-by: Kieran Bingham <[email protected]>
> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks").
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> 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 <[email protected]> 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 <[email protected]>
>> Bisected-by: Kieran Bingham <[email protected]>
>> Tested-by: Kieran Bingham <[email protected]>
>> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks").
>> Signed-off-by: Neil Armstrong <[email protected]>
>> ---
>> 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 <[email protected]>
> Bisected-by: Kieran Bingham <[email protected]>
> Tested-by: Kieran Bingham <[email protected]>
> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks").
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> 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 <[email protected]> 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 <[email protected]>
> Bisected-by: Kieran Bingham <[email protected]>
> Tested-by: Kieran Bingham <[email protected]>
> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks").
This hash too.
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> 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 <[email protected]>
Hi,
On 04/02/2022 15:05, Robert Foss wrote:
> On Wed, 19 Jan 2022 at 13:28, Neil Armstrong <[email protected]> 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 <[email protected]>
>> Bisected-by: Kieran Bingham <[email protected]>
>> Tested-by: Kieran Bingham <[email protected]>
>> Fixes: 0656d1285b79 ("drm/bridge: display-connector: implement bus fmts callbacks").
>
> This hash too.
>
>> Signed-off-by: Neil Armstrong <[email protected]>
>> ---
>> 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 <[email protected]>
Thanks, I'll fix & resend with your r-b.
Neil