Re: [Kgdb-bugreport] [PATCH 2.6.20-rc7] 8139too KGDBoE fix

komal wrote:

Hi all,

	As the discussion was going on about the effects of trapping the
netpoll queue during KGDBoE debugging, I tried avoiding it. So in
eth_pre_exception_handler() I did not set net_poll_trap to 1 and did not
reset it back to 0 in eth_post_exception_handler() 

file drivers/net/kgdboe.c

static void eth_pre_exception_handler(void)
{
        /* Increment the module count when the debugger is active */
        if (!kgdb_connected)
                try_module_get(THIS_MODULE);
//      netpoll_set_trap(1);
}

static void eth_post_exception_handler(void)
{
        /* decrement the module count when the debugger detaches */
        if (!kgdb_connected)
                module_put(THIS_MODULE);
//      netpoll_set_trap(0);
}

    I'm afraid that was a wrong thing to do. We were talking only about 
disabling CONFIG_NETPOLL_TRAP option
   BTW, I don't see how CONFIG_NETPOLL_RX actually could influence anything -- 
looks like it just may be completely removed).

	As i started testing KGDBoe, 1st time I did 
	(gdb)info threads
	and it worked, but after that I set breakpoint
	(gdb)break link_path_walk
	after this any of the commands were not working and the test machine
went in hang state. 
	To provide more information, I am working on an i386/x86_64 Athlon box,
using 2.6.17 kernel and 100Mbps, full-duplex, VIA Rhine network card.

    This driver also seems prone to TX queue overwrites since its TX ring size 
is only 16.

-Regards
 Komal Nawandar

WBR, Sergei