From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ira W. Snyder" Subject: [PATCH 3/3] can: janz-ican3: fix support for CAN_RAW_RECV_OWN_MSGS Date: Mon, 9 Jul 2012 12:56:30 -0700 Message-ID: <1341863790-5645-4-git-send-email-iws@ovro.caltech.edu> References: <1341863790-5645-1-git-send-email-iws@ovro.caltech.edu> Return-path: Received: from ovro.ovro.caltech.edu ([192.100.16.2]:53246 "EHLO ovro.ovro.caltech.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752768Ab2GIT4e (ORCPT ); Mon, 9 Jul 2012 15:56:34 -0400 Received: from localhost (localhost [127.0.0.1]) by ovro.ovro.caltech.edu (Postfix) with ESMTP id 32281222A4 for ; Mon, 9 Jul 2012 12:56:34 -0700 (PDT) In-Reply-To: <1341863790-5645-1-git-send-email-iws@ovro.caltech.edu> Sender: linux-can-owner@vger.kernel.org List-ID: To: linux-can@vger.kernel.org Cc: "Ira W. Snyder" From: "Ira W. Snyder" The Janz VMOD-ICAN3 firmware does not support any sort of TX-done notification or interrupt. The driver previously used the hardware loopback to attempt to work around this deficiency, but this caused all sockets to receive all messages, even if CAN_RAW_RECV_OWN_MSGS is off. Using the new function can_cmp_echo_skb(), we can drop the loopback messages and return the original skbs. This fixes the issues with CAN_RAW_RECV_OWN_MSGS. Signed-off-by: Ira W. Snyder --- drivers/net/can/janz-ican3.c | 56 ++++++++++++++++++++++------------------- 1 files changed, 30 insertions(+), 26 deletions(-) diff --git a/drivers/net/can/janz-ican3.c b/drivers/net/can/janz-ican3.c index 08c893c..a49af40 100644 --- a/drivers/net/can/janz-ican3.c +++ b/drivers/net/can/janz-ican3.c @@ -235,7 +235,6 @@ struct ican3_dev { /* fast host interface */ unsigned int fastrx_start; - unsigned int fastrx_int; unsigned int fastrx_num; unsigned int fasttx_start; unsigned int fasttx_num; @@ -454,7 +453,6 @@ static void __devinit ican3_init_fast_host_interface(struct ican3_dev *mod) /* save the start recv page */ mod->fastrx_start = mod->free_page; mod->fastrx_num = 0; - mod->fastrx_int = 0; /* build a single fast tohost queue descriptor */ memset(&desc, 0, sizeof(desc)); @@ -1150,6 +1148,21 @@ static int ican3_recv_skb(struct ican3_dev *mod) /* convert the ICAN3 frame into Linux CAN format */ ican3_to_can_frame(mod, &desc, cf); + /* + * If this is an ECHO frame received from the hardware loopback + * feature, use the skb saved in the ECHO stack instead. This allows + * the Linux CAN core to support CAN_RAW_RECV_OWN_MSGS correctly. + * + * Also, the netdevice queue needs to be allowed to send packets again. + */ + if (can_cmp_echo_skb(skb, ndev, 0)) { + stats->rx_packets++; + stats->rx_bytes += can_get_echo_skb(ndev, 0); + kfree_skb(skb); + netif_wake_queue(ndev); + goto err_noalloc; + } + /* receive the skb, update statistics */ netif_receive_skb(skb); stats->rx_packets++; @@ -1177,7 +1190,6 @@ static int ican3_napi(struct napi_struct *napi, int budget) { struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi); struct ican3_msg msg; - unsigned long flags; int received = 0; int ret; @@ -1204,14 +1216,6 @@ static int ican3_napi(struct napi_struct *napi, int budget) if (received < budget) napi_complete(napi); - spin_lock_irqsave(&mod->lock, flags); - - /* Wake up the transmit queue if necessary */ - if (netif_queue_stopped(mod->ndev) && ican3_txok(mod)) - netif_wake_queue(mod->ndev); - - spin_unlock_irqrestore(&mod->lock, flags); - /* re-enable interrupt generation */ iowrite8(1 << mod->num, &mod->ctrl->int_enable); return received; @@ -1422,12 +1426,14 @@ static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev) void __iomem *desc_addr; unsigned long flags; + if (can_dropped_invalid_skb(ndev, skb)) + return NETDEV_TX_OK; + spin_lock_irqsave(&mod->lock, flags); /* check that we can actually transmit */ if (!ican3_txok(mod)) { - dev_err(mod->dev, "no free descriptors, stopping queue\n"); - netif_stop_queue(ndev); + dev_err(mod->dev, "BUG: no free descriptors\n"); spin_unlock_irqrestore(&mod->lock, flags); return NETDEV_TX_BUSY; } @@ -1442,6 +1448,16 @@ static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev) can_frame_to_ican3(mod, cf, &desc); /* + * This hardware doesn't have TX-done notifications, so we'll try and + * emulate it the best we can using ECHO skbs. Add the skb to the ECHO + * stack and stop transmitting packets. Upon packet reception, check + * if the ECHO skb and received skb match, and use that to wake the + * queue. + */ + netif_stop_queue(ndev); + can_put_echo_skb(skb, ndev, 0); + + /* * the programming manual says that you must set the IVALID bit, then * interrupt, then set the valid bit. Quite weird, but it seems to be * required for this to work @@ -1462,18 +1478,6 @@ static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev) /* update statistics */ stats->tx_packets++; stats->tx_bytes += cf->can_dlc; - kfree_skb(skb); - - /* - * This hardware doesn't have TX-done notifications, so we'll try and - * emulate it the best we can using ECHO skbs. Get the next TX - * descriptor, and see if we have room to send. If not, stop the queue. - * It will be woken when the ECHO skb for the current packet is recv'd. - */ - - /* copy the control bits of the descriptor */ - if (!ican3_txok(mod)) - netif_stop_queue(ndev); spin_unlock_irqrestore(&mod->lock, flags); return NETDEV_TX_OK; @@ -1654,7 +1658,7 @@ static int __devinit ican3_probe(struct platform_device *pdev) dev = &pdev->dev; /* allocate the CAN device and private data */ - ndev = alloc_candev(sizeof(*mod), 0); + ndev = alloc_candev(sizeof(*mod), 1); if (!ndev) { dev_err(dev, "unable to allocate CANdev\n"); ret = -ENOMEM; -- 1.7.8.6