[PATCH] DM9000: platform dependent fill_ether_addr method

[PATCH] DM9000: platform dependent fill_ether_addr method

[Enrico Scholz]

This patch adds a fill_ether_addr() method to the DM9000 platform data
which can be used to fill in the MAC address in a platform specific manner
(e.g. calculate it out of the serial number).

This method will be called only, when MAC was not set previously (e.g. by
bootloader) or can be read out of the EEPROM.

Having a valid MAC address in early bootstage is necessary e.g. for booting
from network.

Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
---
 drivers/net/dm9000.c   |    4 ++++
 include/linux/dm9000.h |    5 +++++
 2 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/drivers/net/dm9000.c b/drivers/net/dm9000.c
index d63cc93..e668b37 100644
--- a/drivers/net/dm9000.c
+++ b/drivers/net/dm9000.c
@@ -702,6 +702,10 @@ dm9000_probe(struct platform_device *pdev)
 			ndev->dev_addr[i] = ior(db, i+DM9000_PAR);
 	}
 
+	if (pdata && pdata->fill_ether_addr &&
+	    !is_valid_ether_addr(ndev->dev_addr))
+		pdata->fill_ether_addr(ndev->dev_addr);
+
 	if (!is_valid_ether_addr(ndev->dev_addr))
 		dev_warn(db->dev, "%s: Invalid ethernet MAC address. Please "
 			 "set using ifconfig\n", ndev->name);
diff --git a/include/linux/dm9000.h b/include/linux/dm9000.h
index a375046..f763507 100644
--- a/include/linux/dm9000.h
+++ b/include/linux/dm9000.h
@@ -32,6 +32,11 @@ struct dm9000_plat_data {
 	void	(*inblk)(void __iomem *reg, void *data, int len);
 	void	(*outblk)(void __iomem *reg, void *data, int len);
 	void	(*dumpblk)(void __iomem *reg, int len);
+
+	/* An optional method which fills in the MAC address when it could not
+	 * be read from EEPROM. The used method should/can be tagged as
+	 * __devinit. */
+	void 	(*fill_ether_addr)(unsigned char mac[6]);
 };
 
 #endif /* __DM9000_PLATFORM_DATA */
-- 
1.5.4.1

Re: [PATCH] DM9000: platform dependent fill_ether_addr method

[Ben Dooks]

On Fri, Apr 18, 2008 at 12:02:14PM +0200, Enrico Scholz wrote:
> This patch adds a fill_ether_addr() method to the DM9000 platform data
> which can be used to fill in the MAC address in a platform specific manner
> (e.g. calculate it out of the serial number).
> 
> This method will be called only, when MAC was not set previously (e.g. by
> bootloader) or can be read out of the EEPROM.

I belive this has come up on the list a number of times before, and
the general answer is that either the bootloader is at fault for not
initialising the chip, the manufacturer should have shoved an EEPROM
on for configuration. The general answer is that the driver should not
be making up for the fault of the system.

I'm not sure if you can pass the mac via a commandline argument, that
is something you'll have to research for yourself.
 
> Having a valid MAC address in early bootstage is necessary e.g. for booting
> from network.

No, you can load an initramfs to set the mac via ethtool and then
continue with the boot.
 
-- 
Ben (ben@fluff.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'