| Message ID | 1648656179-10347-8-git-send-email-quic_sbillaka@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v6,1/8] drm/msm/dp: Add eDP support via aux_bus | expand |
On Mon, 4 Apr 2022 at 21:32, Sankeerth Billakanti (QUIC) <quic_sbillaka@quicinc.com> wrote: > > Hi Doug, > > > On Wed, Mar 30, 2022 at 9:04 AM Sankeerth Billakanti > > <quic_sbillaka@quicinc.com> wrote: > > > > > > Some eDP sinks or platform boards will not support hpd. > > > This patch adds support for those cases. > > > > You could say more, like: > > > > If we're not using HPD then _both_ the panel node and the eDP controller > > node will have "no-hpd". This tells the eDP panel code to hardcode the > > maximum possible delay for a panel to power up and tells the eDP driver that > > it should continue to do transfers even if HPD isn't asserted. > > > > Okay. I will add it > > > > > > Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com> > > > --- > > > drivers/gpu/drm/msm/dp/dp_catalog.c | 15 ++++++++++++--- > > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c > > > b/drivers/gpu/drm/msm/dp/dp_catalog.c > > > index 1809ce2..8f1fc71 100644 > > > --- a/drivers/gpu/drm/msm/dp/dp_catalog.c > > > +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c > > > @@ -244,10 +244,17 @@ void dp_catalog_aux_update_cfg(struct > > dp_catalog > > > *dp_catalog) > > > > > > int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog > > > *dp_catalog) { > > > - u32 state; > > > + u32 state, hpd_en; > > > struct dp_catalog_private *catalog = container_of(dp_catalog, > > > struct dp_catalog_private, > > > dp_catalog); > > > > > > + hpd_en = dp_read_aux(catalog, REG_DP_DP_HPD_CTRL); > > > + hpd_en &= DP_DP_HPD_CTRL_HPD_EN; > > > + > > > + /* no-hpd case */ > > > + if (!hpd_en) > > > + return 0; > > > + > > > /* poll for hpd connected status every 2ms and timeout after 500ms */ > > > return readl_poll_timeout(catalog->io->dp_controller.aux.base + > > > REG_DP_DP_HPD_INT_STATUS, @@ -586,8 > > > +593,10 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog > > *dp_catalog) > > > reftimer |= DP_DP_HPD_REFTIMER_ENABLE; > > > dp_write_aux(catalog, REG_DP_DP_HPD_REFTIMER, reftimer); > > > > > > - /* Enable HPD */ > > > - dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, > > DP_DP_HPD_CTRL_HPD_EN); > > > + /* Enable HPD if supported*/ > > > + if (!of_property_read_bool(catalog->dev->of_node, "no-hpd")) > > > > I don't think this is a particularly lightweight operation. It's literally iterating > > through all of our device tree properties and doing string compares on them. > > ...but this function is called somewhat often, isn't it? It feels like the kind of > > thing that should happen at probe time and be stored in a boolean. > > > > ...and then you can use that same boolean in > > dp_catalog_aux_wait_for_hpd_connect_state() rather than reading the > > register value, right? > > > It is called twice for DP. Once while booting through a thread scheduled from kms_obj_init > and when resuming from PM suspend. > > With aux_bus addition, this function will be called thrice for eDP. Once during bootup with > aux_bus, then from scheduled event from kms_obj_init and pm resume like DP. > > I will check if we can use a no-hpd Boolean flag instead. As the driver has a separate dp_parser code, it might be a good fit to parse the DT once and then to use boolean flag afterwards.
> > > On Wed, Mar 30, 2022 at 9:04 AM Sankeerth Billakanti > > > <quic_sbillaka@quicinc.com> wrote: > > > > > > > > Some eDP sinks or platform boards will not support hpd. > > > > This patch adds support for those cases. > > > > > > You could say more, like: > > > > > > If we're not using HPD then _both_ the panel node and the eDP > > > controller node will have "no-hpd". This tells the eDP panel code to > > > hardcode the maximum possible delay for a panel to power up and > > > tells the eDP driver that it should continue to do transfers even if HPD > isn't asserted. > > > > > > > Okay. I will add it > > > > > > > > > Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com> > > > > --- > > > > drivers/gpu/drm/msm/dp/dp_catalog.c | 15 ++++++++++++--- > > > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c > > > > b/drivers/gpu/drm/msm/dp/dp_catalog.c > > > > index 1809ce2..8f1fc71 100644 > > > > --- a/drivers/gpu/drm/msm/dp/dp_catalog.c > > > > +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c > > > > @@ -244,10 +244,17 @@ void dp_catalog_aux_update_cfg(struct > > > dp_catalog > > > > *dp_catalog) > > > > > > > > int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog > > > > *dp_catalog) { > > > > - u32 state; > > > > + u32 state, hpd_en; > > > > struct dp_catalog_private *catalog = container_of(dp_catalog, > > > > struct dp_catalog_private, > > > > dp_catalog); > > > > > > > > + hpd_en = dp_read_aux(catalog, REG_DP_DP_HPD_CTRL); > > > > + hpd_en &= DP_DP_HPD_CTRL_HPD_EN; > > > > + > > > > + /* no-hpd case */ > > > > + if (!hpd_en) > > > > + return 0; > > > > + > > > > /* poll for hpd connected status every 2ms and timeout after > 500ms */ > > > > return readl_poll_timeout(catalog->io->dp_controller.aux.base + > > > > REG_DP_DP_HPD_INT_STATUS, @@ > > > > -586,8 > > > > +593,10 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog > > > *dp_catalog) > > > > reftimer |= DP_DP_HPD_REFTIMER_ENABLE; > > > > dp_write_aux(catalog, REG_DP_DP_HPD_REFTIMER, reftimer); > > > > > > > > - /* Enable HPD */ > > > > - dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, > > > DP_DP_HPD_CTRL_HPD_EN); > > > > + /* Enable HPD if supported*/ > > > > + if (!of_property_read_bool(catalog->dev->of_node, > > > > + "no-hpd")) > > > > > > I don't think this is a particularly lightweight operation. It's > > > literally iterating through all of our device tree properties and doing string > compares on them. > > > ...but this function is called somewhat often, isn't it? It feels > > > like the kind of thing that should happen at probe time and be stored in a > boolean. > > > > > > ...and then you can use that same boolean in > > > dp_catalog_aux_wait_for_hpd_connect_state() rather than reading the > > > register value, right? > > > > > It is called twice for DP. Once while booting through a thread > > scheduled from kms_obj_init and when resuming from PM suspend. > > > > With aux_bus addition, this function will be called thrice for eDP. > > Once during bootup with aux_bus, then from scheduled event from > kms_obj_init and pm resume like DP. > > > > I will check if we can use a no-hpd Boolean flag instead. > > As the driver has a separate dp_parser code, it might be a good fit to parse > the DT once and then to use boolean flag afterwards. > Okay. Will add it. > -- > With best wishes > Dmitry
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c index 1809ce2..8f1fc71 100644 --- a/drivers/gpu/drm/msm/dp/dp_catalog.c +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c @@ -244,10 +244,17 @@ void dp_catalog_aux_update_cfg(struct dp_catalog *dp_catalog) int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog) { - u32 state; + u32 state, hpd_en; struct dp_catalog_private *catalog = container_of(dp_catalog, struct dp_catalog_private, dp_catalog); + hpd_en = dp_read_aux(catalog, REG_DP_DP_HPD_CTRL); + hpd_en &= DP_DP_HPD_CTRL_HPD_EN; + + /* no-hpd case */ + if (!hpd_en) + return 0; + /* poll for hpd connected status every 2ms and timeout after 500ms */ return readl_poll_timeout(catalog->io->dp_controller.aux.base + REG_DP_DP_HPD_INT_STATUS, @@ -586,8 +593,10 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog) reftimer |= DP_DP_HPD_REFTIMER_ENABLE; dp_write_aux(catalog, REG_DP_DP_HPD_REFTIMER, reftimer); - /* Enable HPD */ - dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, DP_DP_HPD_CTRL_HPD_EN); + /* Enable HPD if supported*/ + if (!of_property_read_bool(catalog->dev->of_node, "no-hpd")) + dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, + DP_DP_HPD_CTRL_HPD_EN); } u32 dp_catalog_link_is_connected(struct dp_catalog *dp_catalog)
Some eDP sinks or platform boards will not support hpd. This patch adds support for those cases. Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com> --- drivers/gpu/drm/msm/dp/dp_catalog.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)