From: Brian Masney <masneyb@onstation.org>
To: Georgi Djakov <georgi.djakov@linaro.org>
Cc: agross@kernel.org, bjorn.andersson@linaro.org,
robh+dt@kernel.org, mark.rutland@arm.com,
linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 5/5] ARM: dts: qcom: msm8974: add interconnect nodes
Date: Thu, 24 Oct 2019 03:07:30 -0400 [thread overview]
Message-ID: <20191024070730.GA19974@onstation.org> (raw)
In-Reply-To: <c26159f5-e6fe-07f1-51b3-50b72b258846@linaro.org>
On Wed, Oct 23, 2019 at 04:39:21PM +0300, Georgi Djakov wrote:
> On 23.10.19 г. 15:47 ч., Brian Masney wrote:
> > On Wed, Oct 23, 2019 at 02:50:19PM +0300, Georgi Djakov wrote:
> >> On 13.10.19 г. 11:08 ч., Brian Masney wrote:
> >>> Add interconnect nodes that's needed to support bus scaling.
> >>>
> >>> Signed-off-by: Brian Masney <masneyb@onstation.org>
> >>> ---
> >>> arch/arm/boot/dts/qcom-msm8974.dtsi | 60 +++++++++++++++++++++++++++++
> >>> 1 file changed, 60 insertions(+)
> >>>
> >>> diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi b/arch/arm/boot/dts/qcom-msm8974.dtsi
> >>> @@ -1152,6 +1207,11 @@
> >>> "core",
> >>> "vsync";
> >>>
> >>> + interconnects = <&mmssnoc MNOC_MAS_GRAPHICS_3D &bimc BIMC_SLV_EBI_CH0>,
> >>> + <&ocmemnoc OCMEM_VNOC_MAS_GFX3D &ocmemnoc OCMEM_SLV_OCMEM>;
> >>
> >> Who will be the requesting bandwidth to DDR and ocmem? Is it the display or GPU
> >> or both? The above seem like GPU-related interconnects, so maybe these
> >> properties should be in the GPU DT node.
> >
> > The display is what currently requests the interconnect path,
> > specifically mdp5_setup_interconnect() in
> > drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c. The Freedreno GPU bindings
> > currently don't have interconnect support. Maybe this is something that
> > I should add to that driver as well?
>
> The "mdp0-mem" and "mdp1-mem" paths mentioned in the mdp5_kms.c are the two
> interconnects between the display and DDR memory.
OK, I see. Most of the interconnect paths in the downstream MSM 3.4
sources are configured in device tree using the
qcom,msm-bus,vectors-KBps property, which is what I was only looking at
before. The interconnect path for the display is configured directly in
code (drivers/video/msm/mdss/mdss_mdp.c) to setup a path between
MSM_BUS_MASTER_MDP_PORT0 and MSM_BUS_SLAVE_EBI_CH0.
In the upstream kernel, it looks like I'll need to
1) add support for an optional second interconnect path for ocmem to
drivers/gpu/drm/msm/adreno/adreno_gpu.c.
2) add implementations of gpu_get_freq and gpu_get_freq to the
adreno_gpu_funcs struct in drivers/gpu/drm/msm/adreno/a3xx_gpu.c.
Brian
next prev parent reply other threads:[~2019-10-24 7:07 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-13 8:07 [PATCH 0/5] ARM: qcom: add defconfig items and dts nodes Brian Masney
2019-10-13 8:08 ` [PATCH 1/5] ARM: qcom_defconfig: add ocmem support Brian Masney
2019-10-13 8:08 ` [PATCH 2/5] ARM: qcom_defconfig: add msm8974 interconnect support Brian Masney
2019-10-23 8:16 ` Georgi Djakov
2019-10-13 8:08 ` [PATCH 3/5] ARM: qcom_defconfig: add anx78xx HDMI bridge support Brian Masney
2019-10-13 8:08 ` [PATCH 4/5] ARM: dts: qcom: msm8974: add ocmem node Brian Masney
2019-10-13 8:08 ` [PATCH 5/5] ARM: dts: qcom: msm8974: add interconnect nodes Brian Masney
2019-10-23 11:50 ` Georgi Djakov
2019-10-23 12:47 ` Brian Masney
2019-10-23 13:39 ` Georgi Djakov
2019-10-23 13:51 ` Georgi Djakov
2019-10-24 7:07 ` Brian Masney [this message]
2019-10-24 8:27 ` Georgi Djakov
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