PATCH: Re: 2.6.0-test3+sk98lin driver with hardware bug make eth unusable

PATCH: Re: 2.6.0-test3+sk98lin driver with hardware bug make eth unusable

[Ricardo Galli]

On Tuesday 12 August 2003 13:54, Alan Cox shaped the electrons to shout:
> > There is a ASIC bug in several popular motherboards (including ASUS ones)
> > related to TX hardware checksum.
>
> The checksum comes off the SK hardware
>
> > For packets smaller that 56 bytes (payload), as UDP dns queries, the asic
> > generates a bad checksum making the drivers unusable for "normal"
> > Internet usage:
>
> Sounds like broken padding handling for small frames, if so let the sw
> checksum handle them.

Find enclosed the patch to make it a Kconfig option. Just tested, 
at least it works as a workaround.

Regards,

-- 
  ricardo galli       GPG id C8114D34
  http://mnm.uib.es/~gallir/


Patch against 2.6.0-test3

diff -r -u linux-2.6.0-test3/drivers/net/Kconfig linux-2.6.0-test3-new/drivers/net/Kconfig
--- linux-2.6.0-test3/drivers/net/Kconfig	2003-08-10 17:34:29.000000000 +0200
+++ linux-2.6.0-test3-new/drivers/net/Kconfig	2003-08-12 13:47:50.000000000 +0200
@@ -2107,6 +2107,13 @@
 	  say M here and read Documentation/modules.txt. This is recommended.
 	  The module will be called sk98lin.o.

+config SK98LIN_TX_CHECKSUM
+	bool "Use hardware TX checksum"
+	depends on SK98LIN
+	help
+	  Some chips have a hardware bugs that generate wrong
+	  checksums in small packets. If unsure, say No.
+
 config CONFIG_SK98LIN_T1
 	bool "3Com 3C940/3C941 Gigabit Ethernet Adapter"
 	depends on SK98LIN
diff -r -u linux-2.6.0-test3/drivers/net/sk98lin/skge.c linux-2.6.0-test3-new/drivers/net/sk98lin/skge.c
--- linux-2.6.0-test3/drivers/net/sk98lin/skge.c	2003-08-10 17:33:18.000000000 +0200
+++ linux-2.6.0-test3-new/drivers/net/sk98lin/skge.c	2003-08-12 13:50:41.000000000 +0200
@@ -422,8 +422,12 @@
 /* for debuging on x86 only */
 /* #define BREAKPOINT() asm(" int $3"); */

+#ifdef CONFIG_SK98LIN_TX_CHECKSUM
 /* use the transmit hw checksum driver functionality */
-#define USE_SK_TX_CHECKSUM
+ #define USE_SK_TX_CHECKSUM
+#else
+ #undef USE_SK_TX_CHECKSUM
+#endif

 /* use the receive hw checksum driver functionality */
 #define USE_SK_RX_CHECKSUM