Re: [NET]: TSO requires SG, enforce this at device registry.
From: Jeff Garzik <hidden>
Date: 2004-10-25 05:51:00
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Linux Kernel Mailing List wrote:
quoted hunk
diff -Nru a/net/core/dev.c b/net/core/dev.c--- a/net/core/dev.c 2004-10-22 10:15:57 -07:00 +++ b/net/core/dev.c 2004-10-22 10:15:57 -07:00@@ -2871,6 +2871,14 @@ dev->features &= ~NETIF_F_SG; } + /* TSO requires that SG is present as well. */ + if ((dev->features & NETIF_F_TSO) && + !(dev->features & NETIF_F_SG)) { + printk("%s: Dropping NETIF_F_TSO since no SG feature.\n", + dev->name); + dev->features &= ~NETIF_F_TSO; + }
Although this patch is correct, I am pondering whether this fully covers the problems in the field. There are currently two classes of problems I am seeing, that generate real-life bug reports: 1) Given current driver implementations of ethtool ioctls, sysadmin is free to create a combination of bits that are IMHO a bug. One can argue that this is an extension of "root can shoot himself in the foot", so who knows. 2) Programmers writing drivers do not appear to be clear that SG is required to tx-csum/tso, and also, should not be present without one or both of those bits set. Jeff