On 8/26/05, Geoff Levand <[EMAIL PROTECTED]> wrote: > This fixes a major bug in the Sun GEM Ether > driver's netpoll implementation. When both polled > and interrupt driven i/o are used simultaneously, > for example when using kgdb over Ether with active > NFS mounts, a condition easily arises where the bug > is hit. > > The problem is that gem_poll() expects an rx softnet_data > structure to have been allocated (via __netif_rx_schedule()) > prior to its being called. The existing gem driver code > uses gem_interrupt() to set things up for gem_poll(), > but unfortunately, gem_interrupt() doesn't know about > this, and so doesn't allocate the required structure > when it finds no bits set in the interrupt status > register. gem_poll() then move on its way and tries to > delete the non-existent softnet_data structure.
I may be missing something here but I don't see how gem_poll() can move on its way if __netif_rx_schedule() hasen't been called. Wait... in netpoll.c:poll_napi() because bit __LINK_STATE_RX_SCHED is set, correct? To me the bug is that __LINK_STATE_RX_SCHED can be set while __netif_rx_schedule() hasen't be called. Why don't fix it in the simplest way ? See attached patch (absolutely untested). -- Eric
sungem-netpoll-patch
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