| Message ID | 20190528141234.15425-8-laurent.pinchart+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Kieran Bingham |
| Headers | show |
| Series | R-Car DU: LVDS dual-link mode support | expand |
Hi Laurent. On Tue, May 28, 2019 at 05:12:31PM +0300, Laurent Pinchart wrote: > In dual-link LVDS mode, the LVDS1 encoder is used as a companion for > LVDS0, and both encoders transmit data from DU0. The LVDS1 output of DU1 > can't be used in that case, don't create an encoder and connector for > it. > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > --- > Changess since v2: > > - Remove unneeded bridge NULL check > --- > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 12 ++++++++++++ > drivers/gpu/drm/rcar-du/rcar_du_kms.c | 2 +- > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > index 6c91753af7bc..0f00bdfe2366 100644 > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > @@ -16,6 +16,7 @@ > #include "rcar_du_drv.h" > #include "rcar_du_encoder.h" > #include "rcar_du_kms.h" > +#include "rcar_lvds.h" > > /* ----------------------------------------------------------------------------- > * Encoder > @@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > } > } > > + /* > + * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a > + * companion for LVDS0 in dual-link mode. > + */ > + if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) { Both subject and comment above says "On Gen3", but the code looks like it implements "On Gen3 or newer" - due to use of ">=". Looks wrong to me. Sam
Hi Sam, On Tue, May 28, 2019 at 06:42:13PM +0200, Sam Ravnborg wrote: > On Tue, May 28, 2019 at 05:12:31PM +0300, Laurent Pinchart wrote: > > In dual-link LVDS mode, the LVDS1 encoder is used as a companion for > > LVDS0, and both encoders transmit data from DU0. The LVDS1 output of DU1 > > can't be used in that case, don't create an encoder and connector for > > it. > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > > Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > --- > > Changess since v2: > > > > - Remove unneeded bridge NULL check > > --- > > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 12 ++++++++++++ > > drivers/gpu/drm/rcar-du/rcar_du_kms.c | 2 +- > > 2 files changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > index 6c91753af7bc..0f00bdfe2366 100644 > > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > @@ -16,6 +16,7 @@ > > #include "rcar_du_drv.h" > > #include "rcar_du_encoder.h" > > #include "rcar_du_kms.h" > > +#include "rcar_lvds.h" > > > > /* ----------------------------------------------------------------------------- > > * Encoder > > @@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > > } > > } > > > > + /* > > + * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a > > + * companion for LVDS0 in dual-link mode. > > + */ > > + if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) { > > Both subject and comment above says "On Gen3", but the code looks like > it implements "On Gen3 or newer" - due to use of ">=". > Looks wrong to me. Gen3 is the newest generation :-) We thus use >= through the DU and LVDS drivers to prepare for support of Gen4, just in case.
Hi Laurent. On Tue, May 28, 2019 at 07:50:52PM +0300, Laurent Pinchart wrote: > Hi Sam, > > On Tue, May 28, 2019 at 06:42:13PM +0200, Sam Ravnborg wrote: > > On Tue, May 28, 2019 at 05:12:31PM +0300, Laurent Pinchart wrote: > > > In dual-link LVDS mode, the LVDS1 encoder is used as a companion for > > > LVDS0, and both encoders transmit data from DU0. The LVDS1 output of DU1 > > > can't be used in that case, don't create an encoder and connector for > > > it. > > > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > > > Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > --- > > > Changess since v2: > > > > > > - Remove unneeded bridge NULL check > > > --- > > > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 12 ++++++++++++ > > > drivers/gpu/drm/rcar-du/rcar_du_kms.c | 2 +- > > > 2 files changed, 13 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > > index 6c91753af7bc..0f00bdfe2366 100644 > > > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > > @@ -16,6 +16,7 @@ > > > #include "rcar_du_drv.h" > > > #include "rcar_du_encoder.h" > > > #include "rcar_du_kms.h" > > > +#include "rcar_lvds.h" > > > > > > /* ----------------------------------------------------------------------------- > > > * Encoder > > > @@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > > > } > > > } > > > > > > + /* > > > + * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a > > > + * companion for LVDS0 in dual-link mode. > > > + */ > > > + if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) { > > > > Both subject and comment above says "On Gen3", but the code looks like > > it implements "On Gen3 or newer" - due to use of ">=". > > Looks wrong to me. > > Gen3 is the newest generation :-) We thus use >= through the DU and LVDS > drivers to prepare for support of Gen4, just in case. OK, but I guess we agree that the comment needs a small update them. Actually I implicitly reads that it is only from Gen3 onwards that the LVDS1 encoder can be used as a companion. My initial understanding reading the comment was that this implmented a workaround for Gen3 - but it is a workarounf for missing features in older than Gen3. So, assuming this is correct, when trying to specify a companion on older then Gen3 should result in some kind of error/warning? (Maybe it does). Sam
Hi Sam, On Tue, May 28, 2019 at 07:02:42PM +0200, Sam Ravnborg wrote: > On Tue, May 28, 2019 at 07:50:52PM +0300, Laurent Pinchart wrote: > > On Tue, May 28, 2019 at 06:42:13PM +0200, Sam Ravnborg wrote: > >> On Tue, May 28, 2019 at 05:12:31PM +0300, Laurent Pinchart wrote: > >>> In dual-link LVDS mode, the LVDS1 encoder is used as a companion for > >>> LVDS0, and both encoders transmit data from DU0. The LVDS1 output of DU1 > >>> can't be used in that case, don't create an encoder and connector for > >>> it. > >>> > >>> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > >>> Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > >>> Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > >>> --- > >>> Changess since v2: > >>> > >>> - Remove unneeded bridge NULL check > >>> --- > >>> drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 12 ++++++++++++ > >>> drivers/gpu/drm/rcar-du/rcar_du_kms.c | 2 +- > >>> 2 files changed, 13 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > >>> index 6c91753af7bc..0f00bdfe2366 100644 > >>> --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > >>> +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > >>> @@ -16,6 +16,7 @@ > >>> #include "rcar_du_drv.h" > >>> #include "rcar_du_encoder.h" > >>> #include "rcar_du_kms.h" > >>> +#include "rcar_lvds.h" > >>> > >>> /* ----------------------------------------------------------------------------- > >>> * Encoder > >>> @@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > >>> } > >>> } > >>> > >>> + /* > >>> + * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a > >>> + * companion for LVDS0 in dual-link mode. > >>> + */ > >>> + if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) { > >> > >> Both subject and comment above says "On Gen3", but the code looks like > >> it implements "On Gen3 or newer" - due to use of ">=". > >> Looks wrong to me. > > > > Gen3 is the newest generation :-) We thus use >= through the DU and LVDS > > drivers to prepare for support of Gen4, just in case. > > OK, but I guess we agree that the comment needs a small update them. > > Actually I implicitly reads that it is only from Gen3 onwards that the > LVDS1 encoder can be used as a companion. > My initial understanding reading the comment was that this implmented a > workaround for Gen3 - but it is a workarounf for missing features in > older than Gen3. I wouldn't say workaround, it just makes sure that we don't try to support LVDS dual-mode on older SoCs as the feature was added in Gen3 hardware. > So, assuming this is correct, when trying to specify a companion on > older then Gen3 should result in some kind of error/warning? > (Maybe it does). The property is ignored in that case. I could add an error message, but I'm not sure I should, as we don't usually check that DT nodes don't contain any other property than the ones specified in the DT bindings (an automatic DT runtime validator based on the YAML bindings could be interesting ;-)).
Hi Laurent. > > > Gen3 is the newest generation :-) We thus use >= through the DU and LVDS > > > drivers to prepare for support of Gen4, just in case. > > > > OK, but I guess we agree that the comment needs a small update them. > > > > Actually I implicitly reads that it is only from Gen3 onwards that the > > LVDS1 encoder can be used as a companion. > > My initial understanding reading the comment was that this implmented a > > workaround for Gen3 - but it is a workarounf for missing features in > > older than Gen3. > > I wouldn't say workaround, it just makes sure that we don't try to > support LVDS dual-mode on older SoCs as the feature was added in Gen3 > hardware. > > > So, assuming this is correct, when trying to specify a companion on > > older then Gen3 should result in some kind of error/warning? > > (Maybe it does). > > The property is ignored in that case. I could add an error message, but > I'm not sure I should, as we don't usually check that DT nodes don't > contain any other property than the ones specified in the DT bindings > (an automatic DT runtime validator based on the YAML bindings could be > interesting ;-)). Again, thanks for taking your time. This clarifies it nicely. Sam
Hi Laurent, On 28/05/2019 15:12, Laurent Pinchart wrote: > In dual-link LVDS mode, the LVDS1 encoder is used as a companion for > LVDS0, and both encoders transmit data from DU0. The LVDS1 output of DU1 > can't be used in that case, don't create an encoder and connector for > it. > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org> And finally, Last one... Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > --- > Changess since v2: > > - Remove unneeded bridge NULL check > --- > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 12 ++++++++++++ > drivers/gpu/drm/rcar-du/rcar_du_kms.c | 2 +- > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > index 6c91753af7bc..0f00bdfe2366 100644 > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > @@ -16,6 +16,7 @@ > #include "rcar_du_drv.h" > #include "rcar_du_encoder.h" > #include "rcar_du_kms.h" > +#include "rcar_lvds.h" > > /* ----------------------------------------------------------------------------- > * Encoder > @@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > } > } > > + /* > + * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a > + * companion for LVDS0 in dual-link mode. > + */ > + if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) { > + if (rcar_lvds_dual_link(bridge)) { > + ret = -ENOLINK; > + goto done; > + } > + } > + > ret = drm_encoder_init(rcdu->ddev, encoder, &encoder_funcs, > DRM_MODE_ENCODER_NONE, NULL); > if (ret < 0) > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c > index f8f7fff34dff..95c81e59e2f1 100644 > --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c > +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c > @@ -378,7 +378,7 @@ static int rcar_du_encoders_init_one(struct rcar_du_device *rcdu, > } > > ret = rcar_du_encoder_init(rcdu, output, entity); > - if (ret && ret != -EPROBE_DEFER) > + if (ret && ret != -EPROBE_DEFER && ret != -ENOLINK) > dev_warn(rcdu->dev, > "failed to initialize encoder %pOF on output %u (%d), skipping\n", > entity, output, ret); >
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c index 6c91753af7bc..0f00bdfe2366 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c @@ -16,6 +16,7 @@ #include "rcar_du_drv.h" #include "rcar_du_encoder.h" #include "rcar_du_kms.h" +#include "rcar_lvds.h" /* ----------------------------------------------------------------------------- * Encoder @@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, } } + /* + * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a + * companion for LVDS0 in dual-link mode. + */ + if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) { + if (rcar_lvds_dual_link(bridge)) { + ret = -ENOLINK; + goto done; + } + } + ret = drm_encoder_init(rcdu->ddev, encoder, &encoder_funcs, DRM_MODE_ENCODER_NONE, NULL); if (ret < 0) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c index f8f7fff34dff..95c81e59e2f1 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c @@ -378,7 +378,7 @@ static int rcar_du_encoders_init_one(struct rcar_du_device *rcdu, } ret = rcar_du_encoder_init(rcdu, output, entity); - if (ret && ret != -EPROBE_DEFER) + if (ret && ret != -EPROBE_DEFER && ret != -ENOLINK) dev_warn(rcdu->dev, "failed to initialize encoder %pOF on output %u (%d), skipping\n", entity, output, ret);