[PATCH] [5.8 regression] net: ks8851: fix link error

From: Arnd Bergmann <arnd@arndb.de>

An object file cannot be built for both loadable module and built-in
use at the same time:

arm-linux-gnueabi-ld: drivers/net/ethernet/micrel/ks8851_common.o: in function `ks8851_probe_common':
ks8851_common.c:(.text+0xf80): undefined reference to `__this_module'

Change the ks8851_common code to be a standalone module instead,
and use Makefile logic to ensure this is built-in if at least one
of its two users is.

Fixes: 797047f875b5 ("net: ks8851: Implement Parallel bus operations")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Marek sent two other patches to address the problem:
https://lore.kernel.org/netdev/20210116164828.40545-1-marex@denx.de/
https://lore.kernel.org/netdev/20210115134239.126152-1-marex@denx.de/

My version is what I applied locally to my randconfig tree, and
I think this is the cleanest solution.
---
 drivers/net/ethernet/micrel/Makefile        | 6 ++----
 drivers/net/ethernet/micrel/ks8851_common.c | 8 ++++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/micrel/Makefile b/drivers/net/ethernet/micrel/Makefile
index 5cc00d22c708..6ecc4eb30e74 100644
--- a/drivers/net/ethernet/micrel/Makefile
+++ b/drivers/net/ethernet/micrel/Makefile

@@ -4,8 +4,6 @@
 #
 
 obj-$(CONFIG_KS8842) += ks8842.o
-obj-$(CONFIG_KS8851) += ks8851.o
-ks8851-objs = ks8851_common.o ks8851_spi.o
-obj-$(CONFIG_KS8851_MLL) += ks8851_mll.o
-ks8851_mll-objs = ks8851_common.o ks8851_par.o
+obj-$(CONFIG_KS8851) += ks8851_common.o ks8851_spi.o
+obj-$(CONFIG_KS8851_MLL) += ks8851_common.o ks8851_par.o
 obj-$(CONFIG_KSZ884X_PCI) += ksz884x.o

diff --git a/drivers/net/ethernet/micrel/ks8851_common.c b/drivers/net/ethernet/micrel/ks8851_common.c
index 2feed6ce19d3..13d0623c88c6 100644
--- a/drivers/net/ethernet/micrel/ks8851_common.c
+++ b/drivers/net/ethernet/micrel/ks8851_common.c

@@ -1065,6 +1065,7 @@ int ks8851_suspend(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ks8851_suspend);
 
 int ks8851_resume(struct device *dev)
 {

@@ -1078,6 +1079,7 @@ int ks8851_resume(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ks8851_resume);
 #endif
 
 static int ks8851_register_mdiobus(struct ks8851_net *ks, struct device *dev)

@@ -1251,6 +1253,7 @@ int ks8851_probe_common(struct net_device *netdev, struct device *dev,
 err_reg_io:
 	return ret;
 }
+EXPORT_SYMBOL_GPL(ks8851_probe_common);
 
 int ks8851_remove_common(struct device *dev)
 {

@@ -1269,3 +1272,8 @@ int ks8851_remove_common(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ks8851_remove_common);
+
+MODULE_DESCRIPTION("KS8851 Network driver");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");

-- 
2.29.2

On Mon, Jan 25, 2021 at 01:19:20PM +0100, Arnd Bergmann wrote:

From: Arnd Bergmann <arnd@arndb.de>

An object file cannot be built for both loadable module and built-in
use at the same time:

arm-linux-gnueabi-ld: drivers/net/ethernet/micrel/ks8851_common.o: in function `ks8851_probe_common':
ks8851_common.c:(.text+0xf80): undefined reference to `__this_module'

Change the ks8851_common code to be a standalone module instead,
and use Makefile logic to ensure this is built-in if at least one
of its two users is.

Fixes: 797047f875b5 ("net: ks8851: Implement Parallel bus operations")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

On 1/25/21 1:19 PM, Arnd Bergmann wrote:

From: Arnd Bergmann <arnd@arndb.de>

An object file cannot be built for both loadable module and built-in
use at the same time:

arm-linux-gnueabi-ld: drivers/net/ethernet/micrel/ks8851_common.o: in function `ks8851_probe_common':
ks8851_common.c:(.text+0xf80): undefined reference to `__this_module'

Change the ks8851_common code to be a standalone module instead,
and use Makefile logic to ensure this is built-in if at least one
of its two users is.

Fixes: 797047f875b5 ("net: ks8851: Implement Parallel bus operations")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Marek sent two other patches to address the problem:
https://lore.kernel.org/netdev/20210116164828.40545-1-marex@denx.de/
https://lore.kernel.org/netdev/20210115134239.126152-1-marex@denx.de/

My version is what I applied locally to my randconfig tree, and
I think this is the cleanest solution.

If this version works for all the configuration combinations, then 
that's perfect, thanks.