[PATCH] dts: juno: Enable coresight tmc scatter gather in ETR

[PATCH] dts: juno: Enable coresight tmc scatter gather in ETR

[Suzuki K Poulose]

We do not enable scatter-gather mode in the TMC-ETR by default
to prevent malfunctioning of systems where the ETR may not be
properly connected to the memory subsystem to allow for simultaneous
READ/WRITE transactions when used in SG mode. Instead we whitelist
the platforms where we know that it is safe to use the mode.

All revisions of Juno have a proper ETR connection and hence
white list them.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pierlisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm64/boot/dts/arm/juno-base.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi
index ce56a4a..3596e5d 100644
--- a/arch/arm64/boot/dts/arm/juno-base.dtsi
+++ b/arch/arm64/boot/dts/arm/juno-base.dtsi
@@ -199,6 +199,7 @@
 		clocks = <&soc_smc50mhz>;
 		clock-names = "apb_pclk";
 		power-domains = <&scpi_devpd 0>;
+		arm,scatter-gather;
 		port {
 			etr_in_port: endpoint {
 				slave-mode;
-- 
2.7.4

Re: [PATCH] dts: juno: Enable coresight tmc scatter gather in ETR

[Sudeep Holla]

On 11/09/18 09:47, Suzuki K Poulose wrote:
> We do not enable scatter-gather mode in the TMC-ETR by default
> to prevent malfunctioning of systems where the ETR may not be
> properly connected to the memory subsystem to allow for simultaneous
> READ/WRITE transactions when used in SG mode. Instead we whitelist
> the platforms where we know that it is safe to use the mode.
>
> All revisions of Juno have a proper ETR connection and hence
> white list them.
>

Applied conditionally, this conflicts with the patch Mathieu has in his
branch. He needs to drop that so that I can take both of them via ARM SoC.

--
Regards,
Sudeep

Re: [PATCH] dts: juno: Enable coresight tmc scatter gather in ETR

[Mathieu Poirier]

On Tue, 11 Sep 2018 at 04:35, Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On 11/09/18 09:47, Suzuki K Poulose wrote:
> > We do not enable scatter-gather mode in the TMC-ETR by default
> > to prevent malfunctioning of systems where the ETR may not be
> > properly connected to the memory subsystem to allow for simultaneous
> > READ/WRITE transactions when used in SG mode. Instead we whitelist
> > the platforms where we know that it is safe to use the mode.
> >
> > All revisions of Juno have a proper ETR connection and hence
> > white list them.
> >
>
> Applied conditionally, this conflicts with the patch Mathieu has in his
> branch. He needs to drop that so that I can take both of them via ARM SoC.

As I communicated yesterday, I've already dropped that patch from my tree.

>
> --
> Regards,
> Sudeep

Re: [PATCH] dts: juno: Enable coresight tmc scatter gather in ETR

[Sudeep Holla]

On Tue, Sep 11, 2018 at 08:47:27AM -0600, Mathieu Poirier wrote:
> On Tue, 11 Sep 2018 at 04:35, Sudeep Holla <sudeep.holla@arm.com> wrote:
> >
> > On 11/09/18 09:47, Suzuki K Poulose wrote:
> > > We do not enable scatter-gather mode in the TMC-ETR by default
> > > to prevent malfunctioning of systems where the ETR may not be
> > > properly connected to the memory subsystem to allow for simultaneous
> > > READ/WRITE transactions when used in SG mode. Instead we whitelist
> > > the platforms where we know that it is safe to use the mode.
> > >
> > > All revisions of Juno have a proper ETR connection and hence
> > > white list them.
> > >
> >
> > Applied conditionally, this conflicts with the patch Mathieu has in his
> > branch. He needs to drop that so that I can take both of them via ARM SoC.
> 
> As I communicated yesterday, I've already dropped that patch from my tree.

Thanks Mathieu, I have applied both the patches already.

--
Regards,
Sudeep