From: Kevin Hilman <khilman@baylibre.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
Anand Moon <linux.amoon@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org,
Neil Armstrong <narmstrong@baylibre.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
linux-amlogic@lists.infradead.org, Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Jerome Brunet <jbrunet@baylibre.com>
Subject: Re: [RFCv1 5/5] arm64/ARM: configs: Change CONFIG_PWM_MESON from m to y
Date: Mon, 07 Oct 2019 15:57:59 -0700 [thread overview]
Message-ID: <7hsgo4cgeg.fsf@baylibre.com> (raw)
In-Reply-To: <CAFBinCAoJLZj9Kh+SfF4Q+0OCzac2+huon_BU=Q3yE7Fu38U3w@mail.gmail.com>
Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:
> On Mon, Oct 7, 2019 at 3:17 PM Anand Moon <linux.amoon@gmail.com> wrote:
> [...]
>> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
>> index c9a867ac32d4..72f6a7dca0d6 100644
>> --- a/arch/arm64/configs/defconfig
>> +++ b/arch/arm64/configs/defconfig
>> @@ -774,7 +774,7 @@ CONFIG_MPL3115=m
>> CONFIG_PWM=y
>> CONFIG_PWM_BCM2835=m
>> CONFIG_PWM_CROS_EC=m
>> -CONFIG_PWM_MESON=m
>> +CONFIG_PWM_MESON=y
>
> some time ago I submitted a similar patch for the 32-bit SoCs
> it turned that that pwm-meson can be built as module because the
> kernel will run without CPU DVFS as long as the clock and regulator
> drivers are returning -EPROBE_DEFER (-517)
On 64-bit SoCs, the kernel boots with PWM as a module also, but DVFS
only works sometimes, and making it built-in fixes the problem.
Actually, it doesn't fix, it just hides the problem, which is likely a
race or timeout happening during deferred probing.
> did you check whether there's some other problem like some unused
> clock which is being disabled at that moment?
> I've been hunting weird problems in the past where it turned out that
> changing kernel config bits changed the boot timing - that masked the
> original problem
Right, I would definitely prefer to not make this built-in without a lot
more information to *why* this is needed. In figuring that out, we'll
probably find the race/timeout that's the root cause.
Kevin
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
WARNING: multiple messages have this Message-ID (diff)
From: Kevin Hilman <khilman@baylibre.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
Anand Moon <linux.amoon@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org,
Neil Armstrong <narmstrong@baylibre.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
linux-amlogic@lists.infradead.org, Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Jerome Brunet <jbrunet@baylibre.com>
Subject: Re: [RFCv1 5/5] arm64/ARM: configs: Change CONFIG_PWM_MESON from m to y
Date: Mon, 07 Oct 2019 15:57:59 -0700 [thread overview]
Message-ID: <7hsgo4cgeg.fsf@baylibre.com> (raw)
In-Reply-To: <CAFBinCAoJLZj9Kh+SfF4Q+0OCzac2+huon_BU=Q3yE7Fu38U3w@mail.gmail.com>
Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:
> On Mon, Oct 7, 2019 at 3:17 PM Anand Moon <linux.amoon@gmail.com> wrote:
> [...]
>> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
>> index c9a867ac32d4..72f6a7dca0d6 100644
>> --- a/arch/arm64/configs/defconfig
>> +++ b/arch/arm64/configs/defconfig
>> @@ -774,7 +774,7 @@ CONFIG_MPL3115=m
>> CONFIG_PWM=y
>> CONFIG_PWM_BCM2835=m
>> CONFIG_PWM_CROS_EC=m
>> -CONFIG_PWM_MESON=m
>> +CONFIG_PWM_MESON=y
>
> some time ago I submitted a similar patch for the 32-bit SoCs
> it turned that that pwm-meson can be built as module because the
> kernel will run without CPU DVFS as long as the clock and regulator
> drivers are returning -EPROBE_DEFER (-517)
On 64-bit SoCs, the kernel boots with PWM as a module also, but DVFS
only works sometimes, and making it built-in fixes the problem.
Actually, it doesn't fix, it just hides the problem, which is likely a
race or timeout happening during deferred probing.
> did you check whether there's some other problem like some unused
> clock which is being disabled at that moment?
> I've been hunting weird problems in the past where it turned out that
> changing kernel config bits changed the boot timing - that masked the
> original problem
Right, I would definitely prefer to not make this built-in without a lot
more information to *why* this is needed. In figuring that out, we'll
probably find the race/timeout that's the root cause.
Kevin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Kevin Hilman <khilman@baylibre.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
Anand Moon <linux.amoon@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Neil Armstrong <narmstrong@baylibre.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [RFCv1 5/5] arm64/ARM: configs: Change CONFIG_PWM_MESON from m to y
Date: Mon, 07 Oct 2019 15:57:59 -0700 [thread overview]
Message-ID: <7hsgo4cgeg.fsf@baylibre.com> (raw)
In-Reply-To: <CAFBinCAoJLZj9Kh+SfF4Q+0OCzac2+huon_BU=Q3yE7Fu38U3w@mail.gmail.com>
Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:
> On Mon, Oct 7, 2019 at 3:17 PM Anand Moon <linux.amoon@gmail.com> wrote:
> [...]
>> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
>> index c9a867ac32d4..72f6a7dca0d6 100644
>> --- a/arch/arm64/configs/defconfig
>> +++ b/arch/arm64/configs/defconfig
>> @@ -774,7 +774,7 @@ CONFIG_MPL3115=m
>> CONFIG_PWM=y
>> CONFIG_PWM_BCM2835=m
>> CONFIG_PWM_CROS_EC=m
>> -CONFIG_PWM_MESON=m
>> +CONFIG_PWM_MESON=y
>
> some time ago I submitted a similar patch for the 32-bit SoCs
> it turned that that pwm-meson can be built as module because the
> kernel will run without CPU DVFS as long as the clock and regulator
> drivers are returning -EPROBE_DEFER (-517)
On 64-bit SoCs, the kernel boots with PWM as a module also, but DVFS
only works sometimes, and making it built-in fixes the problem.
Actually, it doesn't fix, it just hides the problem, which is likely a
race or timeout happening during deferred probing.
> did you check whether there's some other problem like some unused
> clock which is being disabled at that moment?
> I've been hunting weird problems in the past where it turned out that
> changing kernel config bits changed the boot timing - that masked the
> original problem
Right, I would definitely prefer to not make this built-in without a lot
more information to *why* this is needed. In figuring that out, we'll
probably find the race/timeout that's the root cause.
Kevin
next prev parent reply other threads:[~2019-10-07 22:58 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 13:16 [RFCv1 0/5] Odroid N2 failes to boot using upstream kernel & u-boot Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` [RFCv1 1/5] arm64: dts: meson: Add missing 5V_EN gpio signal for VCC5V regulator Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 14:19 ` Neil Armstrong
2019-10-07 14:19 ` Neil Armstrong
2019-10-07 14:19 ` Neil Armstrong
2019-10-07 15:28 ` Anand Moon
2019-10-07 15:28 ` Anand Moon
2019-10-07 15:28 ` Anand Moon
2019-10-07 13:16 ` [RFCv1 2/5] arm64: dts: meson: Add missing pwm control gpio signal for pwm-regulator Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 15:30 ` Anand Moon
2019-10-07 15:30 ` Anand Moon
2019-10-07 15:30 ` Anand Moon
2019-10-07 13:16 ` [RFCv1 3/5] arm64: dts: meson: Add missing regulator linked to VDDAO_3V3 regulator to FLASH_VDD Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 14:20 ` Neil Armstrong
2019-10-07 15:53 ` Anand Moon
2019-10-07 15:53 ` Anand Moon
2019-10-07 15:53 ` Anand Moon
2019-10-07 15:53 ` Anand Moon
2019-10-07 13:16 ` [RFCv1 4/5] arm64: dts: meson: Add missing regulator linked to VCCV5 regulator to VDDIO_C/TF_IO Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 14:21 ` Neil Armstrong
2019-10-07 14:21 ` Neil Armstrong
2019-10-07 14:21 ` Neil Armstrong
2019-10-07 15:54 ` Anand Moon
2019-10-07 15:54 ` Anand Moon
2019-10-07 15:54 ` Anand Moon
2019-10-07 13:16 ` [RFCv1 5/5] arm64/ARM: configs: Change CONFIG_PWM_MESON from m to y Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 13:16 ` Anand Moon
2019-10-07 14:25 ` Neil Armstrong
2019-10-07 14:25 ` Neil Armstrong
2019-10-07 14:25 ` Neil Armstrong
2019-10-07 15:52 ` Anand Moon
2019-10-07 15:52 ` Anand Moon
2019-10-07 15:52 ` Anand Moon
2019-10-07 20:10 ` Martin Blumenstingl
2019-10-07 20:10 ` Martin Blumenstingl
2019-10-07 20:10 ` Martin Blumenstingl
2019-10-07 22:57 ` Kevin Hilman [this message]
2019-10-07 22:57 ` Kevin Hilman
2019-10-07 22:57 ` Kevin Hilman
2019-10-08 14:38 ` Anand Moon
2019-10-08 14:38 ` Anand Moon
2019-10-08 14:38 ` Anand Moon
2019-10-08 17:40 ` Martin Blumenstingl
2019-10-08 17:40 ` Martin Blumenstingl
2019-10-08 17:40 ` Martin Blumenstingl
2019-10-08 17:40 ` Martin Blumenstingl
2019-10-09 8:48 ` Anand Moon
2019-10-09 8:48 ` Anand Moon
2019-10-09 8:48 ` Anand Moon
2019-10-09 12:04 ` Jerome Brunet
2019-10-09 12:04 ` Jerome Brunet
2019-10-09 12:04 ` Jerome Brunet
2019-10-18 14:04 ` Anand Moon
2019-10-18 14:04 ` Anand Moon
2019-10-18 14:04 ` Anand Moon
2019-10-18 14:13 ` Neil Armstrong
2019-10-18 14:13 ` Neil Armstrong
2019-10-18 14:13 ` Neil Armstrong
2019-10-18 15:21 ` Anand Moon
2019-10-18 15:21 ` Anand Moon
2019-10-18 15:21 ` Anand Moon
2019-10-18 18:10 ` Martin Blumenstingl
2019-10-18 18:10 ` Martin Blumenstingl
2019-10-18 18:10 ` Martin Blumenstingl
2019-10-21 14:11 ` Anand Moon
2019-10-21 14:11 ` Anand Moon
2019-10-21 14:11 ` Anand Moon
2019-10-21 14:25 ` Neil Armstrong
2019-10-21 14:25 ` Neil Armstrong
2019-10-21 14:25 ` Neil Armstrong
2019-10-21 15:41 ` Anand Moon
2019-10-21 15:41 ` Anand Moon
2019-10-21 15:41 ` Anand Moon
2019-10-26 18:56 ` Anand Moon
2019-10-26 18:56 ` Anand Moon
2019-10-26 18:56 ` Anand Moon
2019-10-24 20:20 ` Martin Blumenstingl
2019-10-24 20:20 ` Martin Blumenstingl
2019-10-24 20:20 ` Martin Blumenstingl
2019-10-09 17:05 ` Martin Blumenstingl
2019-10-09 17:05 ` Martin Blumenstingl
2019-10-09 17:05 ` Martin Blumenstingl
2019-10-08 7:19 ` Anand Moon
2019-10-08 7:19 ` Anand Moon
2019-10-08 7:19 ` Anand Moon
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=7hsgo4cgeg.fsf@baylibre.com \
--to=khilman@baylibre.com \
--cc=catalin.marinas@arm.com \
--cc=devicetree@vger.kernel.org \
--cc=jbrunet@baylibre.com \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux.amoon@gmail.com \
--cc=mark.rutland@arm.com \
--cc=martin.blumenstingl@googlemail.com \
--cc=narmstrong@baylibre.com \
--cc=robh+dt@kernel.org \
--cc=will@kernel.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.