[PATCH 0/3] net: phy: prevent linking breakage

There is a linking issue when using phy_register_fixup{,_for_uid,_for_id} and
CONFIG_PHYLIB is not a builtin:

arch/arm/mach-at91/built-in.o: In function `ksz9021rn_phy_fixup':
:(.text+0x1174): undefined reference to `mdiobus_write'
:(.text+0x1188): undefined reference to `mdiobus_write'
:(.text+0x119c): undefined reference to `mdiobus_write'
:(.text+0x11b0): undefined reference to `mdiobus_write'
arch/arm/mach-at91/built-in.o: In function `sama5_dt_device_init':
:(.init.text+0x1e34): undefined reference to `phy_register_fixup_for_uid'

This has been solved for arch/arm/mach-mxs/ and arch/arm/mach-imx/ by testing
IS_BUILTIN(CONFIG_PHYLIB) before calling the functions.

The first patch is an attempt at solving that issue globally.

The following patches remove the unnecessary IS_BUILTIN(CONFIG_PHYLIB) checks.

Quickly greping into the code shows that the issue may arise in:

arch/powerpc/platforms/85xx/mpc85xx_mds.c
arch/arm/mach-davinci/board-dm644x-evm.c
arch/arm/mach-orion5x/dns323-setup.c
arch/arm/mach-at91/board-dt-sama5.c

Alexandre Belloni (3):
  net: phy: prevent linking breakage
  arm: mxs: don't check for CONFIG_PHYLIB as builtin
  arm: imx: don't check for CONFIG_PHYLIB as builtin

 arch/arm/mach-imx/mach-imx6q.c | 23 ++++++++++-------------
 arch/arm/mach-mxs/mach-mxs.c   |  5 ++---
 drivers/net/phy/phy_device.c   |  6 ++++++
 include/linux/phy.h            | 12 ++++++++++++
 4 files changed, 30 insertions(+), 16 deletions(-)

-- 
1.8.1.2

phy_register_fixup{,_for_uid,_for_id} are called from arch/, quite
often, there is no protection to check whether CONFIG_PHYLIB=y which is
the only case where this would work. Having phylib as a module or not
compiled at all will result in that kind of linking failure:

arch/arm/mach-at91/built-in.o: In function `ksz9021rn_phy_fixup':
:(.text+0x1174): undefined reference to `mdiobus_write'
:(.text+0x1188): undefined reference to `mdiobus_write'
:(.text+0x119c): undefined reference to `mdiobus_write'
:(.text+0x11b0): undefined reference to `mdiobus_write'
arch/arm/mach-at91/built-in.o: In function `sama5_dt_device_init':
:(.init.text+0x1e34): undefined reference to `phy_register_fixup_for_uid'

Signed-off-by: Alexandre Belloni <redacted>
---
 drivers/net/phy/phy_device.c |  6 ++++++
 include/linux/phy.h          | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 3657b4a..df36367 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c

@@ -64,6 +64,11 @@ static int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 			     u32 flags, phy_interface_t interface);
 
 /*
+ *  phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this won't
+ *  work unless phylib is compiled in the kernel.
+ */
+#ifdef CONFIG_PHYLIB
+/*
  * Creates a new phy_fixup and adds it to the list
  * @bus_id: A string which matches phydev->dev.bus_id (or PHY_ANY_ID)
  * @phy_uid: Used to match against phydev->phy_id (the UID of the PHY)

@@ -109,6 +114,7 @@ int phy_register_fixup_for_id(const char *bus_id,
 	return phy_register_fixup(bus_id, PHY_ANY_UID, 0xffffffff, run);
 }
 EXPORT_SYMBOL(phy_register_fixup_for_id);
+#endif /* CONFIG_PHYLIB */
 
 /*
  * Returns 1 if fixup matches phydev in bus_id and phy_uid.

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 9e11039..3f998a6 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h

@@ -556,12 +556,24 @@ int phy_start_interrupts(struct phy_device *phydev);
 void phy_print_status(struct phy_device *phydev);
 void phy_device_free(struct phy_device *phydev);
 
+/*
+ *  phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this won't
+ *  work unless phylib is compiled in the kernel.
+ *  Defining stubs allows to prevent linking errors.
+ */
+#ifdef CONFIG_PHYLIB
 int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask,
 		int (*run)(struct phy_device *));
 int phy_register_fixup_for_id(const char *bus_id,
 		int (*run)(struct phy_device *));
 int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
 		int (*run)(struct phy_device *));
+#else
+#define phy_register_fixup(a, b, c, d) do { } while (0)
+#define phy_register_fixup_for_id(a, b) do { } while (0)
+#define phy_register_fixup_for_uid(a, b, c) do { } while (0)
+#endif /* CONFIG_PHYLIB */
+
 int phy_scan_fixups(struct phy_device *phydev);
 
 int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable);

-- 
1.8.1.2

Signed-off-by: Alexandre Belloni <redacted>
---
 arch/arm/mach-imx/mach-imx6q.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 5536fd8..91c3cfb 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c

@@ -99,16 +99,14 @@ soft:
 /* For imx6q sabrelite board: set KSZ9021RN RGMII pad skew */
 static int ksz9021rn_phy_fixup(struct phy_device *phydev)
 {
-	if (IS_BUILTIN(CONFIG_PHYLIB)) {
-		/* min rx data delay */
-		phy_write(phydev, 0x0b, 0x8105);
-		phy_write(phydev, 0x0c, 0x0000);
-
-		/* max rx/tx clock delay, min rx/tx control delay */
-		phy_write(phydev, 0x0b, 0x8104);
-		phy_write(phydev, 0x0c, 0xf0f0);
-		phy_write(phydev, 0x0b, 0x104);
-	}
+	/* min rx data delay */
+	phy_write(phydev, 0x0b, 0x8105);
+	phy_write(phydev, 0x0c, 0x0000);
+
+	/* max rx/tx clock delay, min rx/tx control delay */
+	phy_write(phydev, 0x0b, 0x8104);
+	phy_write(phydev, 0x0c, 0xf0f0);
+	phy_write(phydev, 0x0b, 0x104);
 
 	return 0;
 }

@@ -139,9 +137,8 @@ put_clk:
 
 static void __init imx6q_sabrelite_init(void)
 {
-	if (IS_BUILTIN(CONFIG_PHYLIB))
-		phy_register_fixup_for_uid(PHY_ID_KSZ9021, MICREL_PHY_ID_MASK,
-				ksz9021rn_phy_fixup);
+	phy_register_fixup_for_uid(PHY_ID_KSZ9021, MICREL_PHY_ID_MASK,
+			ksz9021rn_phy_fixup);
 	imx6q_sabrelite_cko1_setup();
 }
 

-- 
1.8.1.2

Signed-off-by: Alexandre Belloni <redacted>
---
 arch/arm/mach-mxs/mach-mxs.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-mxs/mach-mxs.c b/arch/arm/mach-mxs/mach-mxs.c
index 5b62b64..91c2bd2 100644
--- a/arch/arm/mach-mxs/mach-mxs.c
+++ b/arch/arm/mach-mxs/mach-mxs.c

@@ -273,9 +273,8 @@ static void __init apx4devkit_init(void)
 {
 	enable_clk_enet_out();
 
-	if (IS_BUILTIN(CONFIG_PHYLIB))
-		phy_register_fixup_for_uid(PHY_ID_KSZ8051, MICREL_PHY_ID_MASK,
-					   apx4devkit_phy_fixup);
+	phy_register_fixup_for_uid(PHY_ID_KSZ8051, MICREL_PHY_ID_MASK,
+			apx4devkit_phy_fixup);
 }
 
 #define ENET0_MDC__GPIO_4_0	MXS_GPIO_NR(4, 0)

-- 
1.8.1.2

On Mon, May 27, 2013 at 06:18:42PM +0200, Alexandre Belloni wrote:

Use static inline functions here. This breaks if someone does result
checking on the functions which then expands to ret = do {} while (0);
Also we still have type safety for !CONFIG_PHYLIB.

Sascha

-- 
Pengutronix e.K.                           |                             |
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On 27/05/2013 18:39, Sascha Hauer wrote:

On Mon, May 27, 2013 at 06:18:42PM +0200, Alexandre Belloni wrote:

quoted

phy_register_fixup{,_for_uid,_for_id} are called from arch/, quite
often, there is no protection to check whether CONFIG_PHYLIB=y which is
the only case where this would work. Having phylib as a module or not
compiled at all will result in that kind of linking failure:

arch/arm/mach-at91/built-in.o: In function `ksz9021rn_phy_fixup':
:(.text+0x1174): undefined reference to `mdiobus_write'
:(.text+0x1188): undefined reference to `mdiobus_write'
:(.text+0x119c): undefined reference to `mdiobus_write'
:(.text+0x11b0): undefined reference to `mdiobus_write'
arch/arm/mach-at91/built-in.o: In function `sama5_dt_device_init':
:(.init.text+0x1e34): undefined reference to `phy_register_fixup_for_uid'

Signed-off-by: Alexandre Belloni <redacted>
---
 drivers/net/phy/phy_device.c |  6 ++++++
 include/linux/phy.h          | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 3657b4a..df36367 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c

@@ -64,6 +64,11 @@ static int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 			     u32 flags, phy_interface_t interface);
 
 /*
+ *  phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this won't
+ *  work unless phylib is compiled in the kernel.
+ */
+#ifdef CONFIG_PHYLIB
+/*
  * Creates a new phy_fixup and adds it to the list
  * @bus_id: A string which matches phydev->dev.bus_id (or PHY_ANY_ID)
  * @phy_uid: Used to match against phydev->phy_id (the UID of the PHY)

@@ -109,6 +114,7 @@ int phy_register_fixup_for_id(const char *bus_id,
 	return phy_register_fixup(bus_id, PHY_ANY_UID, 0xffffffff, run);
 }
 EXPORT_SYMBOL(phy_register_fixup_for_id);
+#endif /* CONFIG_PHYLIB */
 
 /*
  * Returns 1 if fixup matches phydev in bus_id and phy_uid.

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 9e11039..3f998a6 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h

@@ -556,12 +556,24 @@ int phy_start_interrupts(struct phy_device *phydev);
 void phy_print_status(struct phy_device *phydev);
 void phy_device_free(struct phy_device *phydev);
 
+/*
+ *  phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this won't
+ *  work unless phylib is compiled in the kernel.
+ *  Defining stubs allows to prevent linking errors.
+ */
+#ifdef CONFIG_PHYLIB
 int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask,
 		int (*run)(struct phy_device *));
 int phy_register_fixup_for_id(const char *bus_id,
 		int (*run)(struct phy_device *));
 int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
 		int (*run)(struct phy_device *));
+#else
+#define phy_register_fixup(a, b, c, d) do { } while (0)
+#define phy_register_fixup_for_id(a, b) do { } while (0)
+#define phy_register_fixup_for_uid(a, b, c) do { } while (0)

Use static inline functions here. This breaks if someone does result
checking on the functions which then expands to ret = do {} while (0);
Also we still have type safety for !CONFIG_PHYLIB.

Right, I tried that first but forgot static so I had issues with
redefinition of the functions. I even played with __weak at some point...

I'll wait a bit for comments before sending v2.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Hi,

Le 27 mai 2013 19:38, "Alexandre Belloni" <alexandre.belloni@free-
electrons.com> a écrit :

[snip]

quoted

quoted

+/*
+ *  phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this 

won't

quoted

quoted

+ *  work unless phylib is compiled in the kernel.
+ *  Defining stubs allows to prevent linking errors.
+ */
+#ifdef CONFIG_PHYLIB
 int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask,
             int (*run)(struct phy_device *));
 int phy_register_fixup_for_id(const char *bus_id,
             int (*run)(struct phy_device *));
 int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
             int (*run)(struct phy_device *));
+#else
+#define phy_register_fixup(a, b, c, d) do { } while (0)
+#define phy_register_fixup_for_id(a, b) do { } while (0)
+#define phy_register_fixup_for_uid(a, b, c) do { } while (0)

Use static inline functions here. This breaks if someone does result
checking on the functions which then expands to ret = do {} while (0);
Also we still have

Right, I tried that first but forgot static so I had issues with
redefinition of the functions. I even played with __weak at some point...

You might even want to make these static inlines as mentionned earlier, and 
return something like -ENOTSUPP so that someone using these in board code and 
wondering why they do not work gets a chance to enable CONIFG_PHYLIB.
--
Florian