[PATCH] Yellowfin bug fix for Symbios cards

[PATCH] Yellowfin bug fix for Symbios cards

[Val Henson]

Short version: My last patch to the yellowfin driver forced
full-duplex on for Symbios 10/100 cards, causing severe packet loss on
hubs and some switches.

Long version: Reading the MAC address from the EEPROM didn't work on
the Symbios card, so I turned on the IsGigabit flag to read it
correctly.  This also forces full-duplex on, which is wrong.  So I
added a flag controlling only the MAC address reading behavior and
turned off the IsGigabit flag for Symbios cards.

Patch (against latest 2.4) is at the end of this mail.

Thanks to Tim Moloney for reporting this bug.

-VAL

diff -Nru a/drivers/net/yellowfin.c b/drivers/net/yellowfin.c
--- a/drivers/net/yellowfin.c	Thu Oct 18 20:59:43 2001
+++ b/drivers/net/yellowfin.c	Thu Oct 18 20:59:43 2001
@@ -38,10 +38,13 @@
 	* Fix three endian-ness bugs
 	* Support dual function SYM53C885E ethernet chip
 	
+	LK1.1.5 (val@nmt.edu):
+	* Fix forced full-duplex bug I introduced
+	
 */
 
 #define DRV_NAME	"yellowfin"
-#define DRV_VERSION	"1.05+LK1.1.3"
+#define DRV_VERSION	"1.05+LK1.1.5"
 #define DRV_RELDATE	"May 10, 2001"
 
 #define PFX DRV_NAME ": "
@@ -256,7 +259,7 @@
 };
 enum capability_flags {
 	HasMII=1, FullTxStatus=2, IsGigabit=4, HasMulticastBug=8, FullRxStatus=16,
-	HasMACAddrBug=32,			/* Only on early revs.  */
+	HasMACAddrBug=32, DontUseEeprom=64, /* Only on early revs.  */
 };
 /* The PCI I/O space extent. */
 #define YELLOWFIN_SIZE 0x100
@@ -282,7 +285,7 @@
 	 PCI_IOTYPE, YELLOWFIN_SIZE,
 	 FullTxStatus | IsGigabit | HasMulticastBug | HasMACAddrBug},
 	{"Symbios SYM83C885", { 0x07011000, 0xffffffff},
-	 PCI_IOTYPE, YELLOWFIN_SIZE, HasMII | IsGigabit | FullTxStatus },
+	 PCI_IOTYPE, YELLOWFIN_SIZE, HasMII | DontUseEeprom },
 	{0,},
 };
 
@@ -453,7 +456,7 @@
 #endif
 	irq = pdev->irq;
 
-	if (drv_flags & IsGigabit)
+	if (drv_flags & DontUseEeprom)
 		for (i = 0; i < 6; i++)
 			dev->dev_addr[i] = inb(ioaddr + StnAddr + i);
 	else {

Re: [PATCH] Yellowfin bug fix for Symbios cards

[Jeff Garzik]

Val Henson wrote:
> Long version: Reading the MAC address from the EEPROM didn't work on
> the Symbios card, so I turned on the IsGigabit flag to read it
> correctly.  This also forces full-duplex on, which is wrong.  So I
> added a flag controlling only the MAC address reading behavior and
> turned off the IsGigabit flag for Symbios cards.

Thanks, applied.

Any idea where the MAC address comes from on the Symbios card?

Standard net driver policy is to read the MAC address from the original
source at probe time, typically EEPROM but sometimes in a boot PROM,
firmware console memory, or cardbus CIS.  It is generally preferred to
-not- read the MAC address from the card registers unless you absolutely
have to, since card's copy of the MAC address is easily changeable or
corrupted by rebooting from Windows into Linux or similar things (MacOS
into Linux).

	Jeff


-- 
Jeff Garzik      | Only so many songs can be sung
Building 1024    | with two lips, two lungs, and one tongue.
MandrakeSoft     |         - nomeansno

Re: [PATCH] Yellowfin bug fix for Symbios cards

[Val Henson]

On Thu, Oct 18, 2001 at 11:37:01PM -0400, Jeff Garzik wrote:
> Val Henson wrote:
> > Long version: Reading the MAC address from the EEPROM didn't work on
> > the Symbios card, so I turned on the IsGigabit flag to read it
> > correctly.  This also forces full-duplex on, which is wrong.  So I
> > added a flag controlling only the MAC address reading behavior and
> > turned off the IsGigabit flag for Symbios cards.
> 
> Thanks, applied.
> 
> Any idea where the MAC address comes from on the Symbios card?

I believe our bootloader (Smon) initializes the MAC address.

> Standard net driver policy is to read the MAC address from the original
> source at probe time, typically EEPROM but sometimes in a boot PROM,
> firmware console memory, or cardbus CIS.  It is generally preferred to
> -not- read the MAC address from the card registers unless you absolutely
> have to, since card's copy of the MAC address is easily changeable or
> corrupted by rebooting from Windows into Linux or similar things (MacOS
> into Linux).

Hm, good point.  I should figure out why read_eeprom isn't working and
fix that instead.  Maybe the driver should be changed to attempt to
read the MAC from the eeprom and then read from the registers if that
fails, instead of relying on flags.

By the way, the only other OS that runs on our hardware is VxWorks,
and possibly a few of the more obscure RTOS's...

-VAL

Re: [PATCH] Yellowfin bug fix for Symbios cards

[Jeff Garzik]

Val Henson wrote:
> Hm, good point.  I should figure out why read_eeprom isn't working and
> fix that instead.  Maybe the driver should be changed to attempt to
> read the MAC from the eeprom and then read from the registers if that
> fails, instead of relying on flags.

Yeah.  There is at least one other driver (pcnet32?) that does something
like this...

probe:
	dev->dev_addr[] = read_eeprom();
	if (!is_valid_ether_addr(dev->dev_addr))
		{ read from card registers }

-- 
Jeff Garzik      | Only so many songs can be sung
Building 1024    | with two lips, two lungs, and one tongue.
MandrakeSoft     |         - nomeansno

Re: [PATCH] Yellowfin bug fix for Symbios cards

[Val Henson]

On Fri, Oct 19, 2001 at 12:26:23AM -0400, Jeff Garzik wrote:
> Val Henson wrote:
> > Hm, good point.  I should figure out why read_eeprom isn't working and
> > fix that instead.  Maybe the driver should be changed to attempt to
> > read the MAC from the eeprom and then read from the registers if that
> > fails, instead of relying on flags.
> 
> Yeah.  There is at least one other driver (pcnet32?) that does something
> like this...
> 
> probe:
> 	dev->dev_addr[] = read_eeprom();
> 	if (!is_valid_ether_addr(dev->dev_addr))
> 		{ read from card registers }

Well, I asked our hardware engineers, and the reason read the MAC
address from the EEPROM is that we don't have an EEPROM on our
boards.  Instead, the bootloader reads some stuff out of NVRAM and
writes it into the MAC address registers of the ethernet chip.

I think the above scheme is a good way to read the MAC, but I'd want
to test it on an actual Yellowfin gigabit card before submitting it.
Anyone out here willing to test?

-VAL