LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: khilman@baylibre.com, linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: [PATCH 1/1] ARM: dts: meson8b: fix the operating voltage of the Mali GPU
Date: Sun, 12 May 2019 21:39:36 +0200	[thread overview]
Message-ID: <20190512193936.26557-2-martin.blumenstingl@googlemail.com> (raw)
In-Reply-To: <20190512193936.26557-1-martin.blumenstingl@googlemail.com>

Amlogic's vendor kernel defines an OPP for the GPU on Meson8b boards
with a voltage of 1.15V. It turns out that the vendor kernel relies on
the bootloader to set up the voltage. The bootloader however sets a
fixed voltage of 1.10V.

Amlogic's patched u-boot sources (uboot-2015-01-15-23a3562521) confirm
this:
$ grep -oiE "VDD(EE|AO)_VOLTAGE[ ]+[0-9]+" board/amlogic/configs/m8b_*
  board/amlogic/configs/m8b_m100_v1.h:VDDAO_VOLTAGE            1100
  board/amlogic/configs/m8b_m101_v1.h:VDDAO_VOLTAGE            1100
  board/amlogic/configs/m8b_m102_v1.h:VDDAO_VOLTAGE            1100
  board/amlogic/configs/m8b_m200_v1.h:VDDAO_VOLTAGE            1100
  board/amlogic/configs/m8b_m201_v1.h:VDDEE_VOLTAGE            1100
  board/amlogic/configs/m8b_m201_v1.h:VDDEE_VOLTAGE            1100
  board/amlogic/configs/m8b_m202_v1.h:VDDEE_VOLTAGE            1100

Another hint at this is the VDDEE voltage on the EC-100 and Odroid-C1
boards. The VDDEE regulator supplies the Mali GPU. It's basically a copy
of the VCCK (CPU supply) which means it's limited to 0.86V to 1.14V.

Update the operating voltage of the Mali GPU on Meson8b to 1.10V so it
matches with what the vendor u-boot sets.

Fixes: c3ea80b6138cae ("ARM: dts: meson8b: add the Mali-450 MP2 GPU")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 arch/arm/boot/dts/meson8b.dtsi | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm/boot/dts/meson8b.dtsi b/arch/arm/boot/dts/meson8b.dtsi
index 4b919590dae5..ec67f49116d9 100644
--- a/arch/arm/boot/dts/meson8b.dtsi
+++ b/arch/arm/boot/dts/meson8b.dtsi
@@ -163,23 +163,23 @@
 
 		opp-255000000 {
 			opp-hz = /bits/ 64 <255000000>;
-			opp-microvolt = <1150000>;
+			opp-microvolt = <1100000>;
 		};
 		opp-364300000 {
 			opp-hz = /bits/ 64 <364300000>;
-			opp-microvolt = <1150000>;
+			opp-microvolt = <1100000>;
 		};
 		opp-425000000 {
 			opp-hz = /bits/ 64 <425000000>;
-			opp-microvolt = <1150000>;
+			opp-microvolt = <1100000>;
 		};
 		opp-510000000 {
 			opp-hz = /bits/ 64 <510000000>;
-			opp-microvolt = <1150000>;
+			opp-microvolt = <1100000>;
 		};
 		opp-637500000 {
 			opp-hz = /bits/ 64 <637500000>;
-			opp-microvolt = <1150000>;
+			opp-microvolt = <1100000>;
 			turbo-mode;
 		};
 	};
-- 
2.21.0


  reply	other threads:[~2019-05-12 19:39 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-12 19:39 [PATCH 0/1] ARM: dts: meson8b: another GPU fix Martin Blumenstingl
2019-05-12 19:39 ` Martin Blumenstingl [this message]
2019-05-15  0:01   ` [PATCH 1/1] ARM: dts: meson8b: fix the operating voltage of the Mali GPU Kevin Hilman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190512193936.26557-2-martin.blumenstingl@googlemail.com \
    --to=martin.blumenstingl@googlemail.com \
    --cc=khilman@baylibre.com \
    --cc=linux-amlogic@lists.infradead.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: [PATCH 1/1] ARM: dts: meson8b: fix the operating voltage of the Mali GPU' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).