2024-04-17 00:06:52

by Marijn Suijten

[permalink] [raw]
Subject: [PATCH 0/7] drm/msm: Initial fixes for DUALPIPE (+DSC) topology

This series covers a step-up towards supporting the DUALPIPE DSC
topology, also known as 2:2:2 topology (on active-CTL hardware). It
involves 2 layer mixers, 2 DSC compression encoders, and 2 interfaces
(on DSI, this is called bonded-DSI) where bandwidth constraints (e.g. 4k
panels at 120Hz) require two interfaces to transmit pixel data.

Enabling this topology will be hard(er) than downstream as hacking a
layout type in DTS won't be describing the hardware, but "dynamically"
determining it at runtime may pose some of a challenge that is left to a
future series. Such changes will also involve the 1:1:1 topology needed
for constrained hardware like the Fairphone 5 on SC7280 with access to
only one DSC encoder and thus ruled out of the current 2:2:1 topology.

Likewise, the patches and discussions around improving active-CTL
configuration to support bonded interfaces (that share a single CTL
block) are still in full swing and hence elided from this series, apart
from one patch to fix the ACTIVE_DSC register coding to support updates,
so that it is not forgotten about.

Note that some patches are applicable to DSC-less DUALPIPE bonded mode
as well, such as the patch that allows the slave interface to always be
flushed as that is only supposed to be excluded in the yet-unsupported
PPSPLIT topology.

This series also contains some patches that I'm not too sure about:

drm/msm/dpu: Correct dual-ctl -> dual-intf typo in comment

Downstream doesn't skip the slave INTF flush on active-CTL [1]
(again, just like cmdmode, only when PPSPLIT is enabled [2]), and
even added an extra comment [1] explaining this case. Hence a
dual-intf but single-flush case doesn't seem to exist as there's
only one CTL according to the remainder of the comment.
Maybe the whole comment is wrong?

drm/msm/dsi: Set PHY usescase before registering DSI host

It seems intentional to only set the usecase after
msm_dsi_host_register() in case it fails, so maybe a non-zero `ret`
here should reset the usecase? Likewise should the function call be
moved in !IS_BONDED_DSI() above?

Ideally we also understand what I am doing differently (maybe
wrongly) in my panel driver that makes the PLL turn on and configure
before the usecase has been set, even though these calls are messy
and error-prone nevertheless.

[1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_vid.c?ref_type=heads#L794-804
[2]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_cmd.c?ref_type=heads#L1131-1139

Signed-off-by: Marijn Suijten <[email protected]>
---
Marijn Suijten (7):
drm/msm/dsi: Print dual-DSI-adjusted pclk instead of original mode pclk
drm/msm/dsi: Pass bonded-DSI hdisplay/2 to DSC timing configuration
drm/msm/dpu: Always flush the slave INTF on the CTL
drm/msm/dpu: Allow configuring multiple active DSC blocks
drm/msm/dpu: Correct dual-ctl -> dual-intf typo in comment
drm/msm/dsi: Set PHY usescase before registering DSI host
drm/msm/dpu: Rename `ctx` parameter to `intf` to match other functions

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 ---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 2 +-
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c | 9 ++++++---
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 14 +++++++-------
drivers/gpu/drm/msm/dsi/dsi_host.c | 14 +++++++-------
drivers/gpu/drm/msm/dsi/dsi_manager.c | 15 +++++++++++----
6 files changed, 32 insertions(+), 25 deletions(-)
---
base-commit: 6bd343537461b57f3efe5dfc5fc193a232dfef1e
change-id: 20240416-drm-msm-initial-dualpipe-dsc-fixes-3f0715b03bf4

Best regards,
--
Marijn Suijten <[email protected]>



2024-04-17 00:07:04

by Marijn Suijten

[permalink] [raw]
Subject: [PATCH 3/7] drm/msm/dpu: Always flush the slave INTF on the CTL

As we can clearly see in a downstream kernel [1], flushing the slave INTF
is skipped /only if/ the PPSPLIT topology is active.

However, when DPU was originally submitted to mainline PPSPLIT was no
longer part of it (seems to have been ripped out before submission), but
this clause was incorrectly ported from the original SDE driver. Given
that there is no support for PPSPLIT (currently), flushing the slave
INTF should /never/ be skipped (as the `if (ppsplit && !master) goto
skip;` clause downstream never becomes true).

[1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_cmd.c?ref_type=heads#L1131-1139

Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
Signed-off-by: Marijn Suijten <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index fc1d5736d7fc..489be1c0c704 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -448,9 +448,6 @@ static void dpu_encoder_phys_cmd_enable_helper(

_dpu_encoder_phys_cmd_pingpong_config(phys_enc);

- if (!dpu_encoder_phys_cmd_is_master(phys_enc))
- return;
-
ctl = phys_enc->hw_ctl;
ctl->ops.update_pending_flush_intf(ctl, phys_enc->hw_intf->idx);
}

--
2.44.0


2024-04-17 00:07:45

by Marijn Suijten

[permalink] [raw]
Subject: [PATCH 5/7] drm/msm/dpu: Correct dual-ctl -> dual-intf typo in comment

This comment one line down references a single, "same CTL" that controls
two interfaces, so the comment should clearly describe two interfaces
used with a single active CTL and not "two CTLs".

Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
Signed-off-by: Marijn Suijten <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
index d9e7dbf0499c..7e849fe74801 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
@@ -428,7 +428,7 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
dpu_encoder_phys_vid_setup_timing_engine(phys_enc);

/*
- * For single flush cases (dual-ctl or pp-split), skip setting the
+ * For single flush cases (dual-intf or pp-split), skip setting the
* flush bit for the slave intf, since both intfs use same ctl
* and HW will only flush the master.
*/

--
2.44.0


2024-04-17 00:09:03

by Marijn Suijten

[permalink] [raw]
Subject: [PATCH 6/7] drm/msm/dsi: Set PHY usescase before registering DSI host

Ordering issues here cause an uninitalized (default STANDALONE)
usecase to be programmed (which appears to be a MUX) in some cases
when msm_dsi_host_register() is called, leading to the slave PLL in
bonded-DSI mode to source from a clock parent (dsi1vco) that is off.

This should seemingly not be a problem as the actual dispcc clocks from
DSI1 that are muxed in the clock tree of DSI0 are way further down, this
bit still seems to have an effect on them somehow and causes the right
side of the panel controlled by DSI1 to not function.

In an ideal world this code is refactored to no longer have such
error-prone calls "across subsystems", and instead model the "PLL src"
register field as a regular mux so that changing the clock parents
programmatically or in DTS via `assigned-clock-parents` has the
desired effect.
But for the avid reader, the clocks that we *are* muxing into DSI0's
tree are way further down, so if this bit turns out to be a simple mux
between dsiXvco and out_div, that shouldn't have any effect as this
whole tree is off anyway.

Signed-off-by: Marijn Suijten <[email protected]>
---
drivers/gpu/drm/msm/dsi/dsi_manager.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index af2a287cb3bd..17f43b3c0494 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -85,6 +85,17 @@ static int dsi_mgr_setup_components(int id)
msm_dsi : other_dsi;
struct msm_dsi *slave_link_dsi = IS_MASTER_DSI_LINK(id) ?
other_dsi : msm_dsi;
+
+ /* PLL0 is to drive both 2 DSI link clocks in bonded DSI mode.
+ *
+ * Set the usecase before calling msm_dsi_host_register() to prevent it from
+ * enabling and configuring the usecase (which is just a mux bit) first.
+ */
+ msm_dsi_phy_set_usecase(clk_master_dsi->phy,
+ MSM_DSI_PHY_MASTER);
+ msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
+ MSM_DSI_PHY_SLAVE);
+
/* Register slave host first, so that slave DSI device
* has a chance to probe, and do not block the master
* DSI device's probe.
@@ -100,10 +111,6 @@ static int dsi_mgr_setup_components(int id)
return ret;

/* PLL0 is to drive both 2 DSI link clocks in bonded DSI mode. */
- msm_dsi_phy_set_usecase(clk_master_dsi->phy,
- MSM_DSI_PHY_MASTER);
- msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
- MSM_DSI_PHY_SLAVE);
msm_dsi_host_set_phy_mode(msm_dsi->host, msm_dsi->phy);
msm_dsi_host_set_phy_mode(other_dsi->host, other_dsi->phy);
}

--
2.44.0


2024-04-17 08:19:31

by Dmitry Baryshkov

[permalink] [raw]
Subject: Re: [PATCH 6/7] drm/msm/dsi: Set PHY usescase before registering DSI host

On Wed, 17 Apr 2024 at 02:57, Marijn Suijten
<[email protected]> wrote:
>
> Ordering issues here cause an uninitalized (default STANDALONE)
> usecase to be programmed (which appears to be a MUX) in some cases
> when msm_dsi_host_register() is called, leading to the slave PLL in
> bonded-DSI mode to source from a clock parent (dsi1vco) that is off.
>
> This should seemingly not be a problem as the actual dispcc clocks from
> DSI1 that are muxed in the clock tree of DSI0 are way further down, this
> bit still seems to have an effect on them somehow and causes the right
> side of the panel controlled by DSI1 to not function.
>
> In an ideal world this code is refactored to no longer have such
> error-prone calls "across subsystems", and instead model the "PLL src"
> register field as a regular mux so that changing the clock parents
> programmatically or in DTS via `assigned-clock-parents` has the
> desired effect.
> But for the avid reader, the clocks that we *are* muxing into DSI0's
> tree are way further down, so if this bit turns out to be a simple mux
> between dsiXvco and out_div, that shouldn't have any effect as this
> whole tree is off anyway.
>
> Signed-off-by: Marijn Suijten <[email protected]>
> ---
> drivers/gpu/drm/msm/dsi/dsi_manager.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index af2a287cb3bd..17f43b3c0494 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -85,6 +85,17 @@ static int dsi_mgr_setup_components(int id)
> msm_dsi : other_dsi;
> struct msm_dsi *slave_link_dsi = IS_MASTER_DSI_LINK(id) ?
> other_dsi : msm_dsi;
> +
> + /* PLL0 is to drive both 2 DSI link clocks in bonded DSI mode.
> + *
> + * Set the usecase before calling msm_dsi_host_register() to prevent it from
> + * enabling and configuring the usecase (which is just a mux bit) first.
> + */
> + msm_dsi_phy_set_usecase(clk_master_dsi->phy,
> + MSM_DSI_PHY_MASTER);
> + msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
> + MSM_DSI_PHY_SLAVE);
> +
> /* Register slave host first, so that slave DSI device
> * has a chance to probe, and do not block the master
> * DSI device's probe.
> @@ -100,10 +111,6 @@ static int dsi_mgr_setup_components(int id)
> return ret;
>
> /* PLL0 is to drive both 2 DSI link clocks in bonded DSI mode. */
> - msm_dsi_phy_set_usecase(clk_master_dsi->phy,
> - MSM_DSI_PHY_MASTER);
> - msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
> - MSM_DSI_PHY_SLAVE);
> msm_dsi_host_set_phy_mode(msm_dsi->host, msm_dsi->phy);
> msm_dsi_host_set_phy_mode(other_dsi->host, other_dsi->phy);

Please move msm_dsi_host_set_phy_mode() calls too. Also please update
the non-bonded case.

> }
>
> --
> 2.44.0
>


--
With best wishes
Dmitry

2024-04-17 11:59:05

by Dmitry Baryshkov

[permalink] [raw]
Subject: Re: [PATCH 3/7] drm/msm/dpu: Always flush the slave INTF on the CTL

On Wed, 17 Apr 2024 at 02:57, Marijn Suijten
<[email protected]> wrote:
>
> As we can clearly see in a downstream kernel [1], flushing the slave INTF
> is skipped /only if/ the PPSPLIT topology is active.
>
> However, when DPU was originally submitted to mainline PPSPLIT was no
> longer part of it (seems to have been ripped out before submission), but
> this clause was incorrectly ported from the original SDE driver. Given
> that there is no support for PPSPLIT (currently), flushing the slave
> INTF should /never/ be skipped (as the `if (ppsplit && !master) goto
> skip;` clause downstream never becomes true).
>
> [1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_cmd.c?ref_type=heads#L1131-1139
>
> Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> Signed-off-by: Marijn Suijten <[email protected]>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 ---
> 1 file changed, 3 deletions(-)


Reviewed-by: Dmitry Baryshkov <[email protected]>

--
With best wishes
Dmitry

2024-04-17 12:50:30

by Marijn Suijten

[permalink] [raw]
Subject: Re: [PATCH 6/7] drm/msm/dsi: Set PHY usescase before registering DSI host

On 2024-04-17 11:18:58, Dmitry Baryshkov wrote:
> On Wed, 17 Apr 2024 at 02:57, Marijn Suijten
> <[email protected]> wrote:
> >
> > Ordering issues here cause an uninitalized (default STANDALONE)
> > usecase to be programmed (which appears to be a MUX) in some cases
> > when msm_dsi_host_register() is called, leading to the slave PLL in
> > bonded-DSI mode to source from a clock parent (dsi1vco) that is off.
> >
> > This should seemingly not be a problem as the actual dispcc clocks from
> > DSI1 that are muxed in the clock tree of DSI0 are way further down, this
> > bit still seems to have an effect on them somehow and causes the right
> > side of the panel controlled by DSI1 to not function.
> >
> > In an ideal world this code is refactored to no longer have such
> > error-prone calls "across subsystems", and instead model the "PLL src"
> > register field as a regular mux so that changing the clock parents
> > programmatically or in DTS via `assigned-clock-parents` has the
> > desired effect.
> > But for the avid reader, the clocks that we *are* muxing into DSI0's
> > tree are way further down, so if this bit turns out to be a simple mux
> > between dsiXvco and out_div, that shouldn't have any effect as this
> > whole tree is off anyway.
> >
> > Signed-off-by: Marijn Suijten <[email protected]>
> > ---
> > drivers/gpu/drm/msm/dsi/dsi_manager.c | 15 +++++++++++----
> > 1 file changed, 11 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> > index af2a287cb3bd..17f43b3c0494 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> > @@ -85,6 +85,17 @@ static int dsi_mgr_setup_components(int id)
> > msm_dsi : other_dsi;
> > struct msm_dsi *slave_link_dsi = IS_MASTER_DSI_LINK(id) ?
> > other_dsi : msm_dsi;
> > +
> > + /* PLL0 is to drive both 2 DSI link clocks in bonded DSI mode.
> > + *
> > + * Set the usecase before calling msm_dsi_host_register() to prevent it from
> > + * enabling and configuring the usecase (which is just a mux bit) first.
> > + */
> > + msm_dsi_phy_set_usecase(clk_master_dsi->phy,
> > + MSM_DSI_PHY_MASTER);
> > + msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
> > + MSM_DSI_PHY_SLAVE);
> > +
> > /* Register slave host first, so that slave DSI device
> > * has a chance to probe, and do not block the master
> > * DSI device's probe.
> > @@ -100,10 +111,6 @@ static int dsi_mgr_setup_components(int id)
> > return ret;
> >
> > /* PLL0 is to drive both 2 DSI link clocks in bonded DSI mode. */
> > - msm_dsi_phy_set_usecase(clk_master_dsi->phy,
> > - MSM_DSI_PHY_MASTER);
> > - msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
> > - MSM_DSI_PHY_SLAVE);
> > msm_dsi_host_set_phy_mode(msm_dsi->host, msm_dsi->phy);
> > msm_dsi_host_set_phy_mode(other_dsi->host, other_dsi->phy);
>
> Please move msm_dsi_host_set_phy_mode() calls too.

Ack. Yeah, given that msm_dsi_host_register() causes a modeset and finally the
PLL turning on, these should be set up as well.

For anyone else following along, I have pasted the stacktrace that showcases
the execution flow in the drm/msm tracker:

https://gitlab.freedesktop.org/drm/msm/-/issues/41#note_2376115

Abhinav also pointed out that this PLL source was correctly set in earlier
devcoredump reports, so it might have been a recent development/regression?
This seems to be the only issue originating from it, but folks were adamant that
dsi_mgr_setup_components() (ultimately) would never turn the PLL on, which is
"debunked" by said stacktrace. Maybe other assumptions are affected by this
change?

> Also please update the non-bonded case.

Definitely, as suggested in the cover letter. A similar stacktrace to the above
is acquired on a non-bonded setup, which is also relying on the variable to be
initialized to 0 to select the "local PLL source", rather than being correctly
set via this msm_dsi_phy_set_usecase() configuration.

- Marijn

> > }
> >
> > --
> > 2.44.0
> >
>
>
> --
> With best wishes
> Dmitry

2024-04-17 23:31:34

by Dmitry Baryshkov

[permalink] [raw]
Subject: Re: [PATCH 5/7] drm/msm/dpu: Correct dual-ctl -> dual-intf typo in comment

On Wed, Apr 17, 2024 at 01:57:45AM +0200, Marijn Suijten wrote:
> This comment one line down references a single, "same CTL" that controls
> two interfaces, so the comment should clearly describe two interfaces
> used with a single active CTL and not "two CTLs".
>
> Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> Signed-off-by: Marijn Suijten <[email protected]>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> index d9e7dbf0499c..7e849fe74801 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> @@ -428,7 +428,7 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
> dpu_encoder_phys_vid_setup_timing_engine(phys_enc);
>
> /*
> - * For single flush cases (dual-ctl or pp-split), skip setting the
> + * For single flush cases (dual-intf or pp-split), skip setting the

It should be fixed, but in the other way: it's 'single-ctl'. See
sde_encoder_phys_needs_single_flush().

> * flush bit for the slave intf, since both intfs use same ctl
> * and HW will only flush the master.
> */
>
> --
> 2.44.0
>

--
With best wishes
Dmitry

2024-04-23 18:47:08

by Abhinav Kumar

[permalink] [raw]
Subject: Re: [PATCH 3/7] drm/msm/dpu: Always flush the slave INTF on the CTL



On 4/16/2024 4:57 PM, Marijn Suijten wrote:
> As we can clearly see in a downstream kernel [1], flushing the slave INTF
> is skipped /only if/ the PPSPLIT topology is active.
>
> However, when DPU was originally submitted to mainline PPSPLIT was no
> longer part of it (seems to have been ripped out before submission), but
> this clause was incorrectly ported from the original SDE driver. Given
> that there is no support for PPSPLIT (currently), flushing the slave
> INTF should /never/ be skipped (as the `if (ppsplit && !master) goto
> skip;` clause downstream never becomes true).
>
> [1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_cmd.c?ref_type=heads#L1131-1139
>
> Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> Signed-off-by: Marijn Suijten <[email protected]>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 ---
> 1 file changed, 3 deletions(-)
>

Yes, I agree with this, even though I did think earlier that intf master
flush was sufficient , I cross-checked the docs and this is the right way.


Reviewed-by: Abhinav Kumar <[email protected]>


2024-04-28 21:45:25

by Marijn Suijten

[permalink] [raw]
Subject: Re: [PATCH 5/7] drm/msm/dpu: Correct dual-ctl -> dual-intf typo in comment

On 2024-04-18 02:30:59, Dmitry Baryshkov wrote:
> On Wed, Apr 17, 2024 at 01:57:45AM +0200, Marijn Suijten wrote:
> > This comment one line down references a single, "same CTL" that controls
> > two interfaces, so the comment should clearly describe two interfaces
> > used with a single active CTL and not "two CTLs".
> >
> > Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> > Signed-off-by: Marijn Suijten <[email protected]>
> > ---
> > drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > index d9e7dbf0499c..7e849fe74801 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > @@ -428,7 +428,7 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
> > dpu_encoder_phys_vid_setup_timing_engine(phys_enc);
> >
> > /*
> > - * For single flush cases (dual-ctl or pp-split), skip setting the
> > + * For single flush cases (dual-intf or pp-split), skip setting the
>
> It should be fixed, but in the other way: it's 'single-ctl'. See
> sde_encoder_phys_needs_single_flush().

As written in the cover letter I was unsure about this comment.

You are right that sde_encoder_phys_needs_single_flush() is supposed to return
true in pp-split or single-ctl. However, the second part of the comment (right
below) is in conflict with another patch that I've sent as part of these series:
on a single-ctl setup with dual interfaces, the second INTF needs to be marked
for flushing.

While that observation and fix is for CMD-mode, the exact same comment is found
downstream for video mode:

https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/display-kernel.lnx.5.4.r1-rel/msm/sde/sde_encoder_phys_vid.c?ref_type=heads#L794-804

You were fixing exactly that in one of your preliminary Active-CTL patches by
making dpu_encoder_phys_vid_needs_single_flush() return for Active-CTL, so we
should probably update this comment in the same patch when you send it?

(that is: the flush bit needs to be set for the slave intf in Active-CTL. Before
Active-CTL, a slave encoder would actually have two CTLs and two INTFs where the
flush bit was probably skipped on both slaves?)

On a side-note, since the needs_single_flush callback is used elsehwere, I'm
unsure if that patch affects things in the wrong way since the downstream file
linked above applies the check for CTL_ACTIVE_CFG directly in-line without
affecting the callback.

- Marijn

> > * flush bit for the slave intf, since both intfs use same ctl
> > * and HW will only flush the master.
> > */
> >
> > --
> > 2.44.0
> >
>
> --
> With best wishes
> Dmitry