Re: [PATCH] arm64: dts: mt8192: Add adsp power domain controller
From: AngeloGioacchino Del Regno
Date: Thu Dec 01 2022 - 05:11:11 EST
Il 01/12/22 11:05, Chen-Yu Tsai ha scritto:
On Thu, Dec 1, 2022 at 5:39 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
Il 01/12/22 10:10, Chen-Yu Tsai ha scritto:
On Thu, Dec 1, 2022 at 5:07 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
Il 01/12/22 08:33, Allen-KH Cheng ha scritto:
Add adsp power domain controller node for mt8192 SoC.
Signed-off-by: Allen-KH Cheng <allen-kh.cheng@xxxxxxxxxxxx>
---
Ref: https://lore.kernel.org/all/2ec80bd8-dfef-d2e6-eb41-6e6088043e33@xxxxxxxxxxxxx/
[Allen-KH Cheng <allen-kh.cheng@xxxxxxxxxxxx>]
---
---
arch/arm64/boot/dts/mediatek/mt8192.dtsi | 8 ++++++++
include/dt-bindings/power/mt8192-power.h | 1 +
2 files changed, 9 insertions(+)
Allen, thanks for this one, but it's incomplete...
First of all, you must add the power domain on the driver itself, specifically,
in drivers/soc/mediatek/mt8192-pm-domains.h - otherwise this change will have no
effect!
Actually it's worse. The driver doesn't know about the new power domain,
and so it will fail to probe. We might need to make the power domain driver
fail gracefully and skip unknown power domains.
Right. It's worse. I don't know, though, if gracefully skipping unknown power
domains in the driver would be a good decision... as sometimes error messages
go unnoticed.
When the platform "explodes" instead, you're forced to read that log carefully
and get it working again... Anyway, I'm only thinking out loud, nothing less and
nothing more than that :-)
Me too. :)
By the way, we can probably expand on that topic a bit later, as it's outside of
the scope of this specific change.
Back to topic, if we get one series containing both changes (devicetree, bindings
and driver) with the right Fixes tags and/or Cc stable, we shouldn't have such
issue on backports so we can probably ignore that potential issue, I think? :-)
Everything goes through the soc tree, so they should appear in Linus's tree
and get picked by stable at more or less the same time. I think we would
want the driver change to appear before the dts change, for bisectability's
sake (because of header dependencies and driver errors).
So we probably want:
1. driver + binding header changes
2. dtsi changes
And have these merged through fixes so that the history between them is linear.
Perfect, I fully agree.
ChenYu
Cheers,
Angelo
ChenYu
...Then, as Chen-Yu said, you should also add the power domain to the scp_adsp
clock node as that's solving the lockup issue...
.......and last, but not least: we need a Fixes tag to backport this fix, here
and on the commit that adds the missing power domain in the driver.
Thanks,
Angelo
diff --git a/arch/arm64/boot/dts/mediatek/mt8192.dtsi b/arch/arm64/boot/dts/mediatek/mt8192.dtsi
index 424fc89cc6f7..e71afba871fc 100644
--- a/arch/arm64/boot/dts/mediatek/mt8192.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8192.dtsi
@@ -514,6 +514,14 @@
};
};
};
+
+ power-domain@MT8192_POWER_DOMAIN_ADSP {
+ reg = <MT8192_POWER_DOMAIN_ADSP>;
+ clocks = <&topckgen CLK_TOP_ADSP_SEL>;
+ clock-names = "adsp";
+ mediatek,infracfg = <&infracfg>;
+ #power-domain-cells = <0>;
+ };
};
};
diff --git a/include/dt-bindings/power/mt8192-power.h b/include/dt-bindings/power/mt8192-power.h
index 4eaa53d7270a..63e81cd0d06d 100644
--- a/include/dt-bindings/power/mt8192-power.h
+++ b/include/dt-bindings/power/mt8192-power.h
@@ -28,5 +28,6 @@
#define MT8192_POWER_DOMAIN_CAM_RAWA 18
#define MT8192_POWER_DOMAIN_CAM_RAWB 19
#define MT8192_POWER_DOMAIN_CAM_RAWC 20
+#define MT8192_POWER_DOMAIN_ADSP 21
#endif /* _DT_BINDINGS_POWER_MT8192_POWER_H */
--
AngeloGioacchino Del Regno
Software Engineer
Collabora Ltd.
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