From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wang Xiao W Subject: [PATCH 07/28] fm10k: mbx_update_max_size does not drop all Date: Thu, 10 Sep 2015 12:38:16 +0800 Message-ID: <1441859917-26475-8-git-send-email-xiao.w.wang@intel.com> References: <1441859917-26475-1-git-send-email-xiao.w.wang@intel.com> Cc: Wang Xiao W To: dev@dpdk.org Return-path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 17FB38E91 for ; Thu, 10 Sep 2015 06:39:01 +0200 (CEST) In-Reply-To: <1441859917-26475-1-git-send-email-xiao.w.wang@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" When we call update_max_size, it does not drop all oversized messages. This is due to the difficulty in performing this operation, since it is a FIFO which makes updating anything other than head or tail very difficult. To fix this, modify validate_msg_size to ensure that we error out later when trying to transmit the message that could be oversized. This will generally be a rare condition, as it requires the FIFO to include a message larger than the max_size negotiated during mailbox connect. Note that max_size is always smaller than rx.size, so it should be safe to use here. Also, update the update_max_size function header comment to clearly indicate that it does not drop all oversized messages, but only those at the head of the FIFO. Signed-off-by: Wang Xiao W --- drivers/net/fm10k/base/fm10k_mbx.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/fm10k/base/fm10k_mbx.c b/drivers/net/fm10k/base/fm10k_mbx.c index 12f10f8..0cdd24d 100644 --- a/drivers/net/fm10k/base/fm10k_mbx.c +++ b/drivers/net/fm10k/base/fm10k_mbx.c @@ -344,7 +344,7 @@ STATIC u16 fm10k_mbx_validate_msg_size(struct fm10k_mbx_info *mbx, u16 len) } while (total_len < len); /* message extends out of pushed section, but fits in FIFO */ - if ((len < total_len) && (msg_len <= mbx->rx.size)) + if ((len < total_len) && (msg_len <= mbx->max_size)) return 0; /* return length of invalid section */ @@ -1088,12 +1088,15 @@ STATIC void fm10k_mbx_reset_work(struct fm10k_mbx_info *mbx) } /** - * fm10k_mbx_update_max_size - Update the max_size and drop any large messages + * fm10k_mbx_update_max_size - Update the max_size and drop large messages * @mbx: pointer to mailbox * @size: new value for max_size * - * This function will update the max_size value and drop any outgoing messages - * from the head of the Tx FIFO that are larger than max_size. + * This function updates the max_size value and drops any outgoing messages + * at the head of the Tx FIFO if they are larger than max_size. It does not + * drop all messages, as this is too difficult to parse and remove them from + * the FIFO. Instead, rely on the checking to ensure that messages larger + * than max_size aren't pushed into the memory buffer. **/ STATIC void fm10k_mbx_update_max_size(struct fm10k_mbx_info *mbx, u16 size) { -- 1.9.3