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Fix select-induced Kconfig warning for ZBOOT_ROM

PATCH New Russell King 5 participants 11 messages Jan 2, 2014 – Jan 15, 2014

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Arm (32-bit) Arm sub-architectures Arm i.MX and Layerscape
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Russell King

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#0 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

warning: (ARCH_MULTIPLATFORM && ARCH_CLPS711X && ARCH_PXA &&
SOC_EXYNOS5440 && ARCH_EMEV2) selects AUTO_ZRELADDR which has unmet direct dependencies (!ZBOOT_ROM)

This is because it's possible to have ZBOOT_ROM enabled, but at the same time have another option enabled which selects AUTO_ZRELADDR overriding the !ZBOOT_ROM dependency. Fix this by reversing the dependencies between ZBOOT_ROM and the options which depend on !ZBOOT_ROM.

Signed-off-by Russell King <[email protected]>

---
The autobuilder spotted this on one of its randconfig builds - yet again, it's another illustration of the problems that throwing a "select" statement at a problem is generally a bad idea. Let's make a new year's resolution that we're going to stop throwing "select" at a problem without first thinking about the consequences.

 arch/arm/Kconfig |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
arch/arm/Kconfig +3 -3
index c1f1a7eee953..2ec6bfdf03fd 100644
@@ -1946,6 +1946,7 @@ config ZBOOT_ROM_BSS
 config ZBOOT_ROM
 	bool "Compressed boot loader in ROM/flash"
 	depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
+	depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
 	help
 	  Say Y here if you intend to execute your compressed kernel image
 	  (zImage) directly from ROM or flash.  If unsure, say N.

@@ -1981,7 +1982,7 @@ endchoice
 
 config ARM_APPENDED_DTB
 	bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
-	depends on OF && !ZBOOT_ROM
+	depends on OF
 	help
 	  With this option, the boot code will look for a device tree binary
 	  (DTB) appended to zImage

@@ -2069,7 +2070,7 @@ endchoice
 
 config XIP_KERNEL
 	bool "Kernel Execute-In-Place from ROM"
-	depends on !ZBOOT_ROM && !ARM_LPAE && !ARCH_MULTIPLATFORM
+	depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
 	help
 	  Execute-In-Place allows the kernel to run from non-volatile storage
 	  directly addressable by the CPU, such as NOR flash. This saves RAM

@@ -2132,7 +2133,6 @@ config CRASH_DUMP
 
 config AUTO_ZRELADDR
 	bool "Auto calculation of the decompressed kernel image address"
-	depends on !ZBOOT_ROM
 	help
 	  ZRELADDR is the physical address where the decompressed kernel
 	  image will be placed. If AUTO_ZRELADDR is selected, the address
Signature · 1 line
1.7.4.4
#1 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 4 lines · Russell King

warning: (ARCH_MULTIPLATFORM && ARCH_CLPS711X && ARCH_PXA &&
SOC_EXYNOS5440 && ARCH_EMEV2) selects AUTO_ZRELADDR which has unmet direct dependencies (!ZBOOT_ROM)

Quoted 8 lines

This is because it's possible to have ZBOOT_ROM enabled, but at the same time have another option enabled which selects AUTO_ZRELADDR overriding the !ZBOOT_ROM dependency. Fix this by reversing the dependencies between ZBOOT_ROM and the options which depend on !ZBOOT_ROM.

Signed-off-by Russell King <[email protected]>

---

After this patch I see these warnings with exynos_defconfig

arch/arm/Kconfig:1963:error: recursive dependency detected! arch/arm/Kconfig:1963: symbol ZBOOT_ROM depends on AUTO_ZRELADDR arch/arm/Kconfig:2151: symbol AUTO_ZRELADDR is selected by ZBOOT_ROM

I am not really sure why this happened as I don't see AUTO_ZRELADDR selected by ZBOOT_ROM in Kconfig :)

#2 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 15 lines · On Wednesday 08 January 2014 13:32:35 Viresh Kumar wrote:
Quoted 4 lines · Russell King

warning: (ARCH_MULTIPLATFORM && ARCH_CLPS711X && ARCH_PXA &&
SOC_EXYNOS5440 && ARCH_EMEV2) selects AUTO_ZRELADDR which has unmet direct dependencies (!ZBOOT_ROM)

Quoted 8 lines

This is because it's possible to have ZBOOT_ROM enabled, but at the same time have another option enabled which selects AUTO_ZRELADDR overriding the !ZBOOT_ROM dependency. Fix this by reversing the dependencies between ZBOOT_ROM and the options which depend on !ZBOOT_ROM.

Signed-off-by Russell King <[email protected]>

---

Quoted 8 lines

After this patch I see these warnings with exynos_defconfig

arch/arm/Kconfig:1963:error: recursive dependency detected! arch/arm/Kconfig:1963: symbol ZBOOT_ROM depends on AUTO_ZRELADDR arch/arm/Kconfig:2151: symbol AUTO_ZRELADDR is selected by ZBOOT_ROM

I am not really sure why this happened as I don't see AUTO_ZRELADDR selected by ZBOOT_ROM in Kconfig :)

It's a weird dependency. You need this hunk:

arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR
#3 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

arch/arm/mach-imx/Kconfig config ARCH_MXC · line 9

Quoted 13 lines · Arnd Bergmann

It's a weird dependency. You need this hunk:

arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR

Exynos already has this:

arch/arm/mach-exynos/Kconfig
config SOC_EXYNOS5440

    ...
    select AUTO_ZRELADDR
#4 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 17 lines · On Wednesday 08 January 2014 13:56:38 Viresh Kumar wrote:

arch/arm/mach-imx/Kconfig config ARCH_MXC · line 9

Quoted 13 lines · Arnd Bergmann

It's a weird dependency. You need this hunk:

arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR

Exynos already has this:

Quoted 4 lines

arch/arm/mach-exynos/Kconfig
config SOC_EXYNOS5440

    ...
    select AUTO_ZRELADDR

Yes, that is ok. The problem with the imx dependency is that the kconfig parser needs to know the state of the ZBOOT_ROM symbol in order to decide whether to select AUTO_ZRELADDR or not, but ZBOOT_ROM in turn depends on AUTO_ZRELADDR.

On second thought, we should just remove the 'select AUTO_ZRELADDR' from ARCH_MXC and everything that is multiplatform enabled, since it's already selected by ARCH_MULTIPLATFORM. An interesting question is what to do about the case where you actually want ZBOOT_ROM with a multiplatform enabled machine. We should probably allow that, but it's not possible to express that in Kconfig as long as ZBOOT_ROM depends on !AUTO_ZRELADDR. Obviously such a kernel won't be true multiplatform (it will only work on systems with the right rom address), but I think that's ok as long as it's documented well and not enabled by default. This is similar to what we need to allow non-MMU builds for multiplatform machines.

Arnd

#5 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 24 lines · Arnd Bergmann
Quoted 14 lines

arch/arm/mach-imx/Kconfig config ARCH_MXC · line 9

Quoted 11 lines
arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR

Exynos already has this:

Quoted 4 lines

arch/arm/mach-exynos/Kconfig
config SOC_EXYNOS5440

    ...
    select AUTO_ZRELADDR

Yes, that is ok. The problem with the imx dependency is that the kconfig parser needs to know the state of the ZBOOT_ROM symbol in order to decide whether to select AUTO_ZRELADDR or not, but ZBOOT_ROM in turn depends on AUTO_ZRELADDR.

Quoted 10 lines

On second thought, we should just remove the 'select AUTO_ZRELADDR' from ARCH_MXC and everything that is multiplatform enabled, since it's already selected by ARCH_MULTIPLATFORM. An interesting question is what to do about the case where you actually want ZBOOT_ROM with a multiplatform enabled machine. We should probably allow that, but it's not possible to express that in Kconfig as long as ZBOOT_ROM depends on !AUTO_ZRELADDR. Obviously such a kernel won't be true multiplatform (it will only work on systems with the right rom address), but I think that's ok as long as it's documented well and not enabled by default. This is similar to what we need to allow non-MMU builds for multiplatform machines.

I see.. So, I confirm that above diff fixes my issue.

#6 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

In reply to Arnd Bergmann
Quoted 30 lines · Arnd Bergmann
Quoted 15 lines · On Wednesday 08 January 2014 13:32:35 Viresh Kumar wrote:
Quoted 4 lines · Russell King

warning: (ARCH_MULTIPLATFORM && ARCH_CLPS711X && ARCH_PXA &&
SOC_EXYNOS5440 && ARCH_EMEV2) selects AUTO_ZRELADDR which has unmet direct dependencies (!ZBOOT_ROM)

Quoted 8 lines

This is because it's possible to have ZBOOT_ROM enabled, but at the same time have another option enabled which selects AUTO_ZRELADDR overriding the !ZBOOT_ROM dependency. Fix this by reversing the dependencies between ZBOOT_ROM and the options which depend on !ZBOOT_ROM.

Signed-off-by Russell King <[email protected]>

---

Quoted 8 lines

After this patch I see these warnings with exynos_defconfig

arch/arm/Kconfig:1963:error: recursive dependency detected! arch/arm/Kconfig:1963: symbol ZBOOT_ROM depends on AUTO_ZRELADDR arch/arm/Kconfig:2151: symbol AUTO_ZRELADDR is selected by ZBOOT_ROM

I am not really sure why this happened as I don't see AUTO_ZRELADDR selected by ZBOOT_ROM in Kconfig :)

It's a weird dependency. You need this hunk:

arch/arm/mach-imx/Kconfig config ARCH_MXC · line 9

Quoted 8 lines
arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR

Hi Arnd,

I haven't seen this go into linux-next yet. Do you plan on sending a patch for this?

Thierry
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#7 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 15 lines · Thierry Reding

arch/arm/mach-imx/Kconfig config ARCH_MXC · line 9

Quoted 11 lines · Arnd Bergmann
arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR

Hi Arnd,

Quoted 2 lines

I haven't seen this go into linux-next yet. Do you plan on sending a patch for this?

Maybe someone should respond to this comment from Arnd:

| On second thought, we should just remove the 'select AUTO_ZRELADDR' from
| ARCH_MXC and everything that is multiplatform enabled, since it's already
| selected by ARCH_MULTIPLATFORM.

which I think is the right way to go here. The ARCH_MXC option is hidden when multiplatform is not enabled. When it is enabled, AUTO_ZRELADDR is selected by the multiplatform option. So having a "select AUTO_ZRELADDR" of any kind under ARCH_MXC is entirely redundant.

Signature · 3 lines
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up.  Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".
#8 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 25 lines · Russell King - ARM Linux
Quoted 15 lines · Thierry Reding

arch/arm/mach-imx/Kconfig config ARCH_MXC · line 9

Quoted 11 lines · Arnd Bergmann
arch/arm/mach-imx/Kconfig +1 -1
@@ -3,7 +3,7 @@ config ARCH_MXC
        select ARCH_REQUIRE_GPIOLIB
        select ARM_CPU_SUSPEND if PM
        select ARM_PATCH_PHYS_VIRT
-       select AUTO_ZRELADDR if !ZBOOT_ROM
+       select AUTO_ZRELADDR
        select CLKSRC_MMIO
        select COMMON_CLK
        select GENERIC_ALLOCATOR

Hi Arnd,

Quoted 2 lines

I haven't seen this go into linux-next yet. Do you plan on sending a patch for this?

Maybe someone should respond to this comment from Arnd:

| On second thought, we should just remove the 'select AUTO_ZRELADDR' from
| ARCH_MXC and everything that is multiplatform enabled, since it's already
| selected by ARCH_MULTIPLATFORM.
Quoted 5 lines

which I think is the right way to go here. The ARCH_MXC option is hidden when multiplatform is not enabled. When it is enabled, AUTO_ZRELADDR is selected by the multiplatform option. So having a "select AUTO_ZRELADDR" of any kind under ARCH_MXC is entirely redundant.

It looks like ARCH_MXC is the only one that matches Arnd's requirements. All other platforms that select AUTO_ZRELADDR seem to not support multi- platform.

Below is a patch to remove the line completely. Shall I post that to the patch tracker?

Thierry
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#9 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 12 lines · Thierry Reding

From ee1347c28bb7cb56a3c178321253e38de4bbc676 Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Fri, 10 Jan 2014 17:12:07 +0100
Subject: [PATCH] ARM: Remove redundant select AUTO_ZRELADDR

ARCH_MXC depends on ARCH_MULTI_V4_V5 or ARCH_MULTI_V6_V7, both of which can only be enabled when ARCH_MULTIPLATFORM is selected. If so, then the AUTO_ZRELADDR will already be selected.

Removing the selection of AUTO_ZRELADDR from ARCH_MXC has the additional benefit of getting rid of the following Kconfig error:

Quoted 6 lines

arch/arm/Kconfig:1965:error: recursive dependency detected! arch/arm/Kconfig:1965: symbol ZBOOT_ROM depends on AUTO_ZRELADDR arch/arm/Kconfig:2153: symbol AUTO_ZRELADDR is selected by ZBOOT_ROM

Suggested-by Arnd Bergmann <[email protected]>
Signed-off-by Thierry Reding <[email protected]>
Acked-by Arnd Bergmann <[email protected]>

I'm not sure through which tree this needs to go to make sure that both the arm-soc tree and rmk's arm tree are correct by themselves as well as when they get merged.

Arnd

#10 lore raw

PATCH 1/1 Fix select-induced Kconfig warning for ZBOOT_ROM

Quoted 17 lines · Arnd Bergmann
Quoted 16 lines · Thierry Reding

From ee1347c28bb7cb56a3c178321253e38de4bbc676 Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Fri, 10 Jan 2014 17:12:07 +0100
Subject: [PATCH] ARM: Remove redundant select AUTO_ZRELADDR

ARCH_MXC depends on ARCH_MULTI_V4_V5 or ARCH_MULTI_V6_V7, both of which can only be enabled when ARCH_MULTIPLATFORM is selected. If so, then the AUTO_ZRELADDR will already be selected.

Removing the selection of AUTO_ZRELADDR from ARCH_MXC has the additional benefit of getting rid of the following Kconfig error:

arch/arm/Kconfig:1965:error: recursive dependency detected! arch/arm/Kconfig:1965: symbol ZBOOT_ROM depends on AUTO_ZRELADDR arch/arm/Kconfig:2153: symbol AUTO_ZRELADDR is selected by ZBOOT_ROM

Quoted 8 lines
Quoted 2 lines
Suggested-by Arnd Bergmann <[email protected]>
Signed-off-by Thierry Reding <[email protected]>
Acked-by Arnd Bergmann <[email protected]>

I'm not sure through which tree this needs to go to make sure that both the arm-soc tree and rmk's arm tree are correct by themselves as well as when they get merged.

The original patch went into the arm tree, so I suppose arm-soc isn't really impacted by this unless merged with the arm tree. Therefore I think if this goes in via Russell's tree it should be fine.

Thierry
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