From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: [PATCH] powerpc: ibmveth: Harden driver initilisation for kexec From: Michael Ellerman To: jgarzik Content-Type: text/plain Date: Mon, 18 Sep 2006 14:31:11 +1000 Message-Id: <1158553872.32015.17.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev list , "netdev@vger.kernel.org" , Anton Blanchard Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Jeff, This patch has been floating around for a while now, Santi originally sent it in March: http://www.spinics.net/lists/netdev/msg00471.html You replied saying you thought it was "bonkers", I think I explained why it wasn't, perhaps you disagree. I'm resending it now in the hope you can either give us more info on your objections, or merge it. After a kexec the ibmveth driver will fail when trying to register with the Hypervisor because the previous kernel has not unregistered. So if the registration fails, we unregister and then try again. We don't unconditionally unregister, because we don't want to disturb the regular code path for 99% of users. Signed-off-by: Michael Ellerman Acked-by: Anton Blanchard Signed-off-by: Santiago Leon --- ibmveth.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) Index: to-merge/drivers/net/ibmveth.c =================================================================== --- to-merge.orig/drivers/net/ibmveth.c +++ to-merge/drivers/net/ibmveth.c @@ -437,6 +437,31 @@ static void ibmveth_cleanup(struct ibmve &adapter->rx_buff_pool[i]); } +static int ibmveth_register_logical_lan(struct ibmveth_adapter *adapter, + union ibmveth_buf_desc rxq_desc, u64 mac_address) +{ + int rc, try_again = 1; + + /* After a kexec the adapter will still be open, so our attempt to + * open it will fail. So if we get a failure we free the adapter and + * try again, but only once. */ +retry: + rc = h_register_logical_lan(adapter->vdev->unit_address, + adapter->buffer_list_dma, rxq_desc.desc, + adapter->filter_list_dma, mac_address); + + if (rc != H_SUCCESS && try_again) { + do { + rc = h_free_logical_lan(adapter->vdev->unit_address); + } while (H_IS_LONG_BUSY(rc) || (rc == H_BUSY)); + + try_again = 0; + goto retry; + } + + return rc; +} + static int ibmveth_open(struct net_device *netdev) { struct ibmveth_adapter *adapter = netdev->priv; @@ -503,11 +528,7 @@ static int ibmveth_open(struct net_devic ibmveth_debug_printk("receive q @ 0x%p\n", adapter->rx_queue.queue_addr); - lpar_rc = h_register_logical_lan(adapter->vdev->unit_address, - adapter->buffer_list_dma, - rxq_desc.desc, - adapter->filter_list_dma, - mac_address); + lpar_rc = ibmveth_register_logical_lan(adapter, rxq_desc, mac_address); if(lpar_rc != H_SUCCESS) { ibmveth_error_printk("h_register_logical_lan failed with %ld\n", lpar_rc);