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ARM: SoC fixes (and a cross-arch dt-include fix)

GIT PULL Olof Johansson 5 participants 9 messages May 19, 2017 – Jun 2, 2017 Generic include/asm header files

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The following changes since commit 2ea659a9ef488125eb46da6eb571de5eae5c43f6:

Linux 4.12-rc1 (2017-05-13 13:19:49 -0700)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc.git tags/armsoc-fixes

for you to fetch changes up to 6bf1c2d26716dcd483699cc62474e49d164c5563:

arm64: dts: rockchip: fix include reference (2017-05-19 14:12:00 +0200)

----------------------------------------------------------------
ARM: SoC fixes (and a cross-arch dt-include fix)

We had a small batch of fixes before -rc1, but here is a larger one. It contains a backmerge of 4.12-rc1 since some of the downstream branches we merge had that as base; at the same time we already had merged contents before -rc1 and rebase wasn't the right solution.

A mix of random smaller fixes and a few things worth pointing out:

- We've started telling people to avoid cross-tree shared branches if all they're doing is picking up one or two DT-used constants from a shared include file, and instead to use the numeric values on first submission. Follow-up moving over to symbolic names are sent in right after -rc1, i.e. here. It's only a few minor patches of this type.

- Linus Walleij and others are resurrecting the 'Gemini' platform, and wanted a cut-down platform-specific defconfig for it. So I picked that up for them.

- Rob Herring ran 'savedefconfig' on arm64, it's a bit churny but it helps people to prepare patches since it's a pain when defconfig and current savedefconfig contents differs too much.

- Devicetree additions for some pinctrl drivers for Armada that were merged this window. I'd have preferred to see those earlier but it's not a huge deail.

The biggest change worth pointing out though since it's touching other parts of the tree: We added prefixes to be used when cross-including DT contents between arm64 and arm, allowing someone to #include <arm/foo.dtsi> from arm64, and likewise. As part of that, we needed arm/foo.dtsi to work on arm as well. The way I suggested this to Heiko resulted in a recursive symlink.

Instead, I've now moved it out of arch/*/boot/dts/include, into a shared location under scripts/dtc. While I was at it, I consolidated so all architectures now behave the same way in this manner.

Rob Herring (DT maintainer) has acked it. I cc:d most other arch maintainers but nobody seems to care much; it doesn't really affect them since functionality is unchanged for them by default.

----------------------------------------------------------------
Adam Ford (1):
ARM: dts: LogicPD Torpedo: Fix camera pin mux

Andreas Kemnade (1):
ARM: dts: gta04: fix polarity of clocks for mcbsp4

Arnd Bergmann (11):
ARM: omap2+: make omap4_get_cpu1_ns_pa_addr declaration usable
Merge tag 'v4.11-next-fixes' of https://github.com/mbgg/linux-mediatek into fixes Merge tag 'renesas-fixes-for-v4.12' of https://git.kernel.org/.../horms/renesas into fixes Merge tag 'mvebu-dt64-4.12-3' of git://git.infradead.org/linux-mvebu into fixes Merge tag 'mvebu-arm64-4.12-1' of git://git.infradead.org/linux-mvebu into fixes Merge branch 'tee/initial-merge' into fixes
tee: add ARM_SMCCC dependency
soc: imx: add PM dependency for IMX7_PM_DOMAINS
ARM: remove duplicate 'const' annotations'
firmware: ti_sci: fix strncat length check
arm64: dts: rockchip: fix include reference

Baruch Siach (4):
ARM: dts: bcm2835: fix uart0 pinctrl node names
ARM: dts: bcm2835: fix i2c0 pins
ARM: dts: bcm2835: fix uart0/uart1 pins
ARM: dts: bcm2835: add index to the ethernet alias

Fabio Estevam (1):
ARM: dts: imx53-qsrb: Pulldown PMIC IRQ pin

Florian Fainelli (2):
Merge tag 'bcm2835-dt-next-2017-03-30' into devicetree/fixes
soc: bcm: brcmstb: Correctly match 7435 SoC

Geert Uytterhoeven (1):
soc: renesas: Provide dummy rcar_rst_read_mode_pins() for compile-testing

Gregory CLEMENT (3):
arm64: marvell: enable the Armada 37xx pinctrl driver
ARM64: dts: marvell: Add pinctrl nodes for Armada 3700
ARM64: dts: marvell: armada37xx: add pinctrl definition

Hans Verkuil (1):
ARM: dts: omap4: enable CEC pin for Pandaboard A4 and ES

John Crispin (1):
arm: dts: mt7623: add clock-frequency to the a7 timer node to mt7623.dtsi

Keerthy (1):
ARM: dts: dra7: Add power hold and power controller properties to palmas

Leonard Crestez (1):
ARM: dts: imx6sx-sdb: Remove OPP override

Linus Walleij (1):
ARM: configs: add a gemini defconfig

Olof Johansson (6):
Merge tag 'v4.12-rc1' into fixes
devicetree: Move include prefixes from arch to separate directory
Merge tag 'arm-soc/for-4.12/devicetree-fixes' of http://github.com/Broadcom/stblinux into fixes Merge tag 'arm-soc/for-4.12/drivers-fixes' of http://github.com/Broadcom/stblinux into fixes Merge tag 'imx-fixes-4.12' of git://git.kernel.org/.../shawnguo/linux into fixes Merge tag 'omap-for-v4.12/fixes-v2-signed' of git://git.kernel.org/.../tmlind/linux-omap into fixes

Ravikumar Kattekola (1):
ARM: dts: dra7: Reduce cpu thermal shutdown temperature

Rob Herring (2):
arm64: defconfig: sync with savedefconfig
arm64: defconfig: enable options needed for QCom DB410c board

Tony Lindgren (1):
memory: omap-gpmc: Fix debug output for access width

yong mao (1):
ARM64: dts: mediatek: configure some fixed mmc parameters

 arch/arm/boot/dts/bcm283x-rpi-smsc9512.dtsi       |   2 +-
 arch/arm/boot/dts/bcm283x-rpi-smsc9514.dtsi       |   2 +-
 arch/arm/boot/dts/bcm283x.dtsi                    |  22 +++--
 arch/arm/boot/dts/dra7-evm.dts                    |   2 +
 arch/arm/boot/dts/dra7.dtsi                       |   4 +
 arch/arm/boot/dts/imx53-qsrb.dts                  |   2 +-
 arch/arm/boot/dts/imx6sx-sdb.dts                  |  17 ----
 arch/arm/boot/dts/include/arm                     |   1 -
 arch/arm/boot/dts/include/arm64                   |   1 -
 arch/arm/boot/dts/include/dt-bindings             |   1 -
 arch/arm/boot/dts/logicpd-torpedo-37xx-devkit.dts |   6 +-
 arch/arm/boot/dts/mt7623.dtsi                     |   2 +
 arch/arm/boot/dts/omap3-gta04.dtsi                |   3 +-
 arch/arm/boot/dts/omap4-panda-a4.dts              |   2 +-
 arch/arm/boot/dts/omap4-panda-es.dts              |   2 +-
 arch/arm/configs/gemini_defconfig                 |  68 ++++++++++++++
 arch/arm/mach-at91/pm.c                           |   2 +-
 arch/arm/mach-bcm/bcm_kona_smc.c                  |   2 +-
 arch/arm/mach-cns3xxx/core.c                      |   2 +-
 arch/arm/mach-omap2/common.h                      |   3 +-
 arch/arm/mach-omap2/omap-mpuss-lowpower.c         |  10 +-
 arch/arm/mach-omap2/omap-smp.c                    |  11 ++-
 arch/arm/mach-omap2/prm_common.c                  |   2 +-
 arch/arm/mach-omap2/vc.c                          |   2 +-
 arch/arm/mach-spear/time.c                        |   2 +-
 arch/arm64/Kconfig.platforms                      |   5 +
 arch/arm64/boot/dts/include/arm                   |   1 -
 arch/arm64/boot/dts/include/arm64                 |   1 -
 arch/arm64/boot/dts/include/dt-bindings           |   1 -
 arch/arm64/boot/dts/marvell/armada-3720-db.dts    |   8 ++
 arch/arm64/boot/dts/marvell/armada-37xx.dtsi      |  73 ++++++++++++++-
 arch/arm64/boot/dts/mediatek/mt8173-evb.dts       |   3 +
 arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts |   2 +-
 arch/arm64/configs/defconfig                      | 106 ++++++++++------------
 arch/cris/boot/dts/include/dt-bindings            |   1 -
 arch/metag/boot/dts/include/dt-bindings           |   1 -
 arch/mips/boot/dts/include/dt-bindings            |   1 -
 arch/powerpc/boot/dts/include/dt-bindings         |   1 -
 drivers/firmware/ti_sci.c                         |   3 +-
 drivers/memory/omap-gpmc.c                        |   2 +-
 drivers/soc/bcm/brcmstb/common.c                  |   2 +-
 drivers/soc/imx/Kconfig                           |   3 +-
 drivers/tee/Kconfig                               |   1 +
 include/linux/soc/renesas/rcar-rst.h              |   5 +
 scripts/Makefile.lib                              |   2 +-
 scripts/dtc/include-prefixes/arc                  |   1 +
 scripts/dtc/include-prefixes/arm                  |   1 +
 scripts/dtc/include-prefixes/arm64                |   1 +
 scripts/dtc/include-prefixes/c6x                  |   1 +
 scripts/dtc/include-prefixes/cris                 |   1 +
 scripts/dtc/include-prefixes/dt-bindings          |   1 +
 scripts/dtc/include-prefixes/h8300                |   1 +
 scripts/dtc/include-prefixes/metag                |   1 +
 scripts/dtc/include-prefixes/microblaze           |   1 +
 scripts/dtc/include-prefixes/mips                 |   1 +
 scripts/dtc/include-prefixes/nios2                |   1 +
 scripts/dtc/include-prefixes/openrisc             |   1 +
 scripts/dtc/include-prefixes/powerpc              |   1 +
 scripts/dtc/include-prefixes/sh                   |   1 +
 scripts/dtc/include-prefixes/xtensa               |   1 +
 60 files changed, 281 insertions(+), 129 deletions(-)
 delete mode 120000 arch/arm/boot/dts/include/arm
 delete mode 120000 arch/arm/boot/dts/include/arm64
 delete mode 120000 arch/arm/boot/dts/include/dt-bindings
 create mode 100644 arch/arm/configs/gemini_defconfig
 delete mode 120000 arch/arm64/boot/dts/include/arm
 delete mode 120000 arch/arm64/boot/dts/include/arm64
 delete mode 120000 arch/arm64/boot/dts/include/dt-bindings
 delete mode 120000 arch/cris/boot/dts/include/dt-bindings
 delete mode 120000 arch/metag/boot/dts/include/dt-bindings
 delete mode 120000 arch/mips/boot/dts/include/dt-bindings
 delete mode 120000 arch/powerpc/boot/dts/include/dt-bindings
 create mode 120000 scripts/dtc/include-prefixes/arc
 create mode 120000 scripts/dtc/include-prefixes/arm
 create mode 120000 scripts/dtc/include-prefixes/arm64
 create mode 120000 scripts/dtc/include-prefixes/c6x
 create mode 120000 scripts/dtc/include-prefixes/cris
 create mode 120000 scripts/dtc/include-prefixes/dt-bindings
 create mode 120000 scripts/dtc/include-prefixes/h8300
 create mode 120000 scripts/dtc/include-prefixes/metag
 create mode 120000 scripts/dtc/include-prefixes/microblaze
 create mode 120000 scripts/dtc/include-prefixes/mips
 create mode 120000 scripts/dtc/include-prefixes/nios2
 create mode 120000 scripts/dtc/include-prefixes/openrisc
 create mode 120000 scripts/dtc/include-prefixes/powerpc
 create mode 120000 scripts/dtc/include-prefixes/sh
 create mode 120000 scripts/dtc/include-prefixes/xtensa
#1 lore raw
Quoted 5 lines · Olof Johansson

- We've started telling people to avoid cross-tree shared branches if all they're doing is picking up one or two DT-used constants from a shared include file, and instead to use the numeric values on first submission. Follow-up moving over to symbolic names are sent in right after -rc1, i.e. here. It's only a few minor patches of this type.

OK it seems like a reasonable process.

It's not like I can think about anything better.

I was more opting for doing things this way:

- Create bindings and <dt-bindings/foo/bar.h> merge it into the foo subsystem.

- Merge driver into drivers/foo/bar.c that use <dt-bindings/foo/bar.h>

- Submit DTS patch to ARM SoC (or whetever) using only numerical values.

- After the merge window, follow up with a patch replacing the numerical constants with #defines from <dt-bindings/foo/bar.h>

An alternative would obviously be to wait for the next merge window after merging the driver patch but I guess people are too impatient to do that (including me).

We discussed cross-tree dependencies a bit on ksummit-discuss but this solution was not mentioned back then.

Yours,
Linus Walleij

#2 lore raw

[adding ksummit-discuss]

Quoted 17 lines · Linus Walleij
Quoted 5 lines · Olof Johansson

- We've started telling people to avoid cross-tree shared branches if all they're doing is picking up one or two DT-used constants from a shared include file, and instead to use the numeric values on first submission. Follow-up moving over to symbolic names are sent in right after -rc1, i.e. here. It's only a few minor patches of this type.

OK it seems like a reasonable process.

It's not like I can think about anything better.

I was more opting for doing things this way:

- Create bindings and <dt-bindings/foo/bar.h> merge it into the foo subsystem.

Quoted 7 lines

- Merge driver into drivers/foo/bar.c that use <dt-bindings/foo/bar.h>

- Submit DTS patch to ARM SoC (or whetever) using only numerical values.

- After the merge window, follow up with a patch replacing the numerical constants with #defines from <dt-bindings/foo/bar.h>

You're describing exactly what we've been pushing people towards.

If it's just a few simple references it's not significantly more awkward, and decouples merges and removes need for stable branches. Essentially we've become slightly more lax in what we're willing to consider _right after_ -rc1 to include these tweaks (and often patches to turn on new drivers in defconfigs).

If the amount of contents grows too large we might need to tweak things further, maybe with something pre-rc1 but that's more awkward.

Quoted 3 lines

An alternative would obviously be to wait for the next merge window after merging the driver patch but I guess people are too impatient to do that (including me).

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

Quoted 2 lines

We discussed cross-tree dependencies a bit on ksummit-discuss but this solution was not mentioned back then.

I thought it was, but I wasn't fully engaged in the discussion. We've also only started this over the last release or two so it's early to tell just how well it'll work in reality. Cc:ing the list.

-Olof

#3 lore raw
Quoted 47 lines · Olof Johansson

[adding ksummit-discuss]

Quoted 17 lines · Linus Walleij
Quoted 5 lines · Olof Johansson

- We've started telling people to avoid cross-tree shared branches if all they're doing is picking up one or two DT-used constants from a shared include file, and instead to use the numeric values on first submission. Follow-up moving over to symbolic names are sent in right after -rc1, i.e. here. It's only a few minor patches of this type.

OK it seems like a reasonable process.

It's not like I can think about anything better.

I was more opting for doing things this way:

- Create bindings and <dt-bindings/foo/bar.h> merge it into the foo subsystem.

Quoted 7 lines

- Merge driver into drivers/foo/bar.c that use <dt-bindings/foo/bar.h>

- Submit DTS patch to ARM SoC (or whetever) using only numerical values.

- After the merge window, follow up with a patch replacing the numerical constants with #defines from <dt-bindings/foo/bar.h>

You're describing exactly what we've been pushing people towards.

If it's just a few simple references it's not significantly more awkward, and decouples merges and removes need for stable branches. Essentially we've become slightly more lax in what we're willing to consider _right after_ -rc1 to include these tweaks (and often patches to turn on new drivers in defconfigs).

If the amount of contents grows too large we might need to tweak things further, maybe with something pre-rc1 but that's more awkward.

Quoted 3 lines

An alternative would obviously be to wait for the next merge window after merging the driver patch but I guess people are too impatient to do that (including me).

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

Quoted 6 lines
Quoted 2 lines

We discussed cross-tree dependencies a bit on ksummit-discuss but this solution was not mentioned back then.

I thought it was, but I wasn't fully engaged in the discussion. We've also only started this over the last release or two so it's early to tell just how well it'll work in reality. Cc:ing the list.

Yeah, this sounds like a good step towards improving what I've complained about, while still keeping topic/shared stable branch proliferation under control.
-Daniel

Signature · 3 lines
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
#4 lore raw
In reply to Olof Johansson

Hi Olof,

Quoted 36 lines · Olof Johansson
Quoted 16 lines · Linus Walleij
Quoted 5 lines · Olof Johansson

- We've started telling people to avoid cross-tree shared branches if all they're doing is picking up one or two DT-used constants from a shared include file, and instead to use the numeric values on first submission. Follow-up moving over to symbolic names are sent in right after -rc1, i.e. here. It's only a few minor patches of this type.

OK it seems like a reasonable process.

It's not like I can think about anything better.

I was more opting for doing things this way:

- Create bindings and <dt-bindings/foo/bar.h> merge it into the foo subsystem.

Quoted 7 lines

- Merge driver into drivers/foo/bar.c that use <dt-bindings/foo/bar.h>

- Submit DTS patch to ARM SoC (or whetever) using only numerical values.

- After the merge window, follow up with a patch replacing the numerical constants with #defines from <dt-bindings/foo/bar.h>

You're describing exactly what we've been pushing people towards.

If it's just a few simple references it's not significantly more awkward, and decouples merges and removes need for stable branches. Essentially we've become slightly more lax in what we're willing to consider _right after_ -rc1 to include these tweaks (and often patches to turn on new drivers in defconfigs).

If the amount of contents grows too large we might need to tweak things further, maybe with something pre-rc1 but that's more awkward.

Quoted 7 lines
Quoted 3 lines

An alternative would obviously be to wait for the next merge window after merging the driver patch but I guess people are too impatient to do that (including me).

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

The above works fine for new support, or for new platforms.

There's still support being migrated from platform code to DT, which requires three steps:
1. New DT-aware driver support,
2. DT update to use the new driver support,
3. Clean up platform code after optional DTB backwards compatibility grace period,
To make matters worse, 1 may conflict with the existing platform code, and 2 must sometimes not be done before 1. Hence you may need three kernel releases.
So we're already planning now what to clean up for v4.15 ;-)

Would it be acceptable to do step 2 in the same release, after the driver support has entered in -rc1? I know this is more than just replacing numbers by symbolic values.

Thanks!

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

maintainer
#5 lore raw
Quoted 22 lines · Geert Uytterhoeven
Quoted 6 lines · Olof Johansson
Quoted 1 line · Linus Walleij

On Fri, May 19, 2017 at 9:34 PM, Olof Johansson <[email protected]> wrote:

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

The above works fine for new support, or for new platforms.

There's still support being migrated from platform code to DT, which requires three steps:
1. New DT-aware driver support,
2. DT update to use the new driver support,
3. Clean up platform code after optional DTB backwards compatibility grace period,
To make matters worse, 1 may conflict with the existing platform code, and 2 must sometimes not be done before 1. Hence you may need three kernel releases.
So we're already planning now what to clean up for v4.15 ;-)

Quoted 3 lines

Would it be acceptable to do step 2 in the same release, after the driver support has entered in -rc1? I know this is more than just replacing numbers by symbolic values.

I'd say it really depends on the individual case. Do you have a particular platform in mind? E.g. For some of the more obsolete platforms that Linus Walleij has worked on over time, we have sometimes relaxed the rules about clean bisection and just merged everything in parallel, knowing that nobody else was likely to run that code on a vanilla kernel anyway.

Arnd

#8 lore raw
In reply to Geert Uytterhoeven
Quoted 60 lines · Geert Uytterhoeven

Hi Olof,

Quoted 36 lines · Olof Johansson
Quoted 16 lines · Linus Walleij
Quoted 5 lines · Olof Johansson

- We've started telling people to avoid cross-tree shared branches if all they're doing is picking up one or two DT-used constants from a shared include file, and instead to use the numeric values on first submission. Follow-up moving over to symbolic names are sent in right after -rc1, i.e. here. It's only a few minor patches of this type.

OK it seems like a reasonable process.

It's not like I can think about anything better.

I was more opting for doing things this way:

- Create bindings and <dt-bindings/foo/bar.h> merge it into the foo subsystem.

Quoted 7 lines

- Merge driver into drivers/foo/bar.c that use <dt-bindings/foo/bar.h>

- Submit DTS patch to ARM SoC (or whetever) using only numerical values.

- After the merge window, follow up with a patch replacing the numerical constants with #defines from <dt-bindings/foo/bar.h>

You're describing exactly what we've been pushing people towards.

If it's just a few simple references it's not significantly more awkward, and decouples merges and removes need for stable branches. Essentially we've become slightly more lax in what we're willing to consider _right after_ -rc1 to include these tweaks (and often patches to turn on new drivers in defconfigs).

If the amount of contents grows too large we might need to tweak things further, maybe with something pre-rc1 but that's more awkward.

Quoted 7 lines
Quoted 3 lines

An alternative would obviously be to wait for the next merge window after merging the driver patch but I guess people are too impatient to do that (including me).

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

The above works fine for new support, or for new platforms.

There's still support being migrated from platform code to DT, which requires three steps:
1. New DT-aware driver support,
2. DT update to use the new driver support,
3. Clean up platform code after optional DTB backwards compatibility grace period,
To make matters worse, 1 may conflict with the existing platform code, and 2 must sometimes not be done before 1. Hence you may need three kernel releases.
So we're already planning now what to clean up for v4.15 ;-)

Quoted 3 lines

Would it be acceptable to do step 2 in the same release, after the driver support has entered in -rc1? I know this is more than just replacing numbers by symbolic values.

Part of why we encouraged a more stretched-out approach in your case was that we used to get quite a few dependent branches for Renesas platforms, and when there were things to fixup, a lot of respins and churn. So we asked to move a little slower to avoid DoS:ing ourselves.

As far as the above process goes: 1+2 is exactly what we're encouraging others to do. The main discussion point here is when there's substantial shared dt-includes between driver and the DTS contents. Most of the time, for most drivers, that's usually not the case. As Arnd suggested, it might be helpful to have specific examples to discuss here.

-Olof

#6 lore raw
In reply to Arnd Bergmann

Hi Arnd,

Quoted 27 lines · Arnd Bergmann
Quoted 21 lines · Geert Uytterhoeven
Quoted 6 lines · Olof Johansson
Quoted 1 line · Linus Walleij

On Fri, May 19, 2017 at 9:34 PM, Olof Johansson <[email protected]> wrote:

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

The above works fine for new support, or for new platforms.

There's still support being migrated from platform code to DT, which requires three steps:
1. New DT-aware driver support,
2. DT update to use the new driver support,
3. Clean up platform code after optional DTB backwards compatibility grace period,
To make matters worse, 1 may conflict with the existing platform code, and 2 must sometimes not be done before 1. Hence you may need three kernel releases.
So we're already planning now what to clean up for v4.15 ;-)

Quoted 3 lines

Would it be acceptable to do step 2 in the same release, after the driver support has entered in -rc1? I know this is more than just replacing numbers by symbolic values.

Quoted 5 lines

I'd say it really depends on the individual case. Do you have a particular platform in mind? E.g. For some of the more obsolete platforms that Linus Walleij has worked on over time, we have sometimes relaxed the rules about clean bisection and just merged everything in parallel, knowing that nobody else was likely to run that code on a vanilla kernel anyway.

This is for Renesas R-Car Gen2 SoCs, so we do care about DT backward compatibility (for a while), and about bisection.

Last headache was "[PATCH v4 00/23] soc: renesas: Add R-Car RST driver for obtaining mode pin state" (https://lkml.org/lkml/2016/10/21/500). This used a shared immutable branch, but that caused several merge conflicts.

Next one will be smaller, as it's not really moving functionality from platform code to DT, but switching to a new and better clock driver framework, so there's only the dependency of DT on the new driver
"[PATCH v2 00/10] clk: renesas: rcar-gen2: Add new CPG/MSSR drivers"
(https://lkml.org/lkml/2017/5/19/212)

I'll go create an inventory of stuff in platform code for Renesas SoCs that still needs to be converted to DT...

Thanks!

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

maintainer
#7 lore raw
Quoted 30 lines · Geert Uytterhoeven

Hi Arnd,

Quoted 27 lines · Arnd Bergmann
Quoted 24 lines · Geert Uytterhoeven
Quoted 6 lines · Olof Johansson
Quoted 1 line · Linus Walleij

On Fri, May 19, 2017 at 9:34 PM, Olof Johansson <[email protected]> wrote:

Yeah, asking people to spread out across releases would remove dependencies a lot, but it would also slow down progress and frustrate a lot of contributors so we don't do that.

The above works fine for new support, or for new platforms.

There's still support being migrated from platform code to DT, which requires three steps:
1. New DT-aware driver support,
2. DT update to use the new driver support,
3. Clean up platform code after optional DTB backwards compatibility grace period,
To make matters worse, 1 may conflict with the existing platform code, and 2 must sometimes not be done before 1. Hence you may need three kernel releases.
So we're already planning now what to clean up for v4.15 ;-)

Would it be acceptable to do step 2 in the same release, after the driver support has entered in -rc1? I know this is more than just replacing numbers by symbolic values.

Quoted 8 lines
Quoted 5 lines

I'd say it really depends on the individual case. Do you have a particular platform in mind? E.g. For some of the more obsolete platforms that Linus Walleij has worked on over time, we have sometimes relaxed the rules about clean bisection and just merged everything in parallel, knowing that nobody else was likely to run that code on a vanilla kernel anyway.

This is for Renesas R-Car Gen2 SoCs, so we do care about DT backward compatibility (for a while), and about bisection.

Ok, I see.

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Last headache was "[PATCH v4 00/23] soc: renesas: Add R-Car RST driver for obtaining mode pin state" (https://lkml.org/lkml/2016/10/21/500). This used a shared immutable branch, but that caused several merge conflicts.

Next one will be smaller, as it's not really moving functionality from platform code to DT, but switching to a new and better clock driver framework, so there's only the dependency of DT on the new driver
"[PATCH v2 00/10] clk: renesas: rcar-gen2: Add new CPG/MSSR drivers"
(https://lkml.org/lkml/2017/5/19/212)

Ok, so there is already a working driver for these chips, but you want to move to a better driver and binding. That's all fine, but I'm not sure about why you want to do this faster at all. Presumably you want to use the new driver quickly so you can add new platforms not using the old driver, but then you'd have a couple of years of grace period before removing the old driver for customers with existing out of tree dts files, so I would assume that waiting another release or two before moving the DT files over is not adding a huge burden.

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I'll go create an inventory of stuff in platform code for Renesas SoCs that still needs to be converted to DT...

That would certainly be helpful, yes.

Arnd