From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Roger B. Melton" Subject: Re: [PATCH 4/4] ethdev: check support for rx_queue_count and descriptor_done fns Date: Fri, 12 Jun 2015 13:32:56 -0400 Message-ID: <557B17C8.3090300@cisco.com> References: <1434108496-1993-1-git-send-email-bruce.richardson@intel.com> <1434108496-1993-5-git-send-email-bruce.richardson@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org To: Bruce Richardson Return-path: Received: from alln-iport-3.cisco.com (alln-iport-3.cisco.com [173.37.142.90]) by dpdk.org (Postfix) with ESMTP id 28778C312 for ; Fri, 12 Jun 2015 19:32:52 +0200 (CEST) In-Reply-To: <1434108496-1993-5-git-send-email-bruce.richardson@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" Hi Bruce, Comment in-line. Regards, Roger On 6/12/15 7:28 AM, Bruce Richardson wrote: > The functions rte_eth_rx_queue_count and rte_eth_descriptor_done are > supported by very few PMDs. Therefore, it is best to check for support > for the functions in the ethdev library, so as to avoid crashes > at run-time if the application goes to use those APIs. The performance > impact of this change should be very small as this is a predictable > branch in the function. > > Signed-off-by: Bruce Richardson > --- > lib/librte_ether/rte_ethdev.h | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h > index 827ca3e..9ad1b6a 100644 > --- a/lib/librte_ether/rte_ethdev.h > +++ b/lib/librte_ether/rte_ethdev.h > @@ -2496,6 +2496,8 @@ rte_eth_rx_burst(uint8_t port_id, uint16_t queue_id, > * The queue id on the specific port. > * @return > * The number of used descriptors in the specific queue. > + * NOTE: if function is not supported by device this call > + * returns (uint32_t)-ENOTSUP > */ > static inline uint32_t Why not change the return type to int32_t? In this way, the caller isn't required to make the assumption that a large queue count indicates an error. < 0 means error, other wise it's a valid queue count. This approach would be consistent with other APIs. > rte_eth_rx_queue_count(uint8_t port_id, uint16_t queue_id) > @@ -2507,8 +2509,9 @@ rte_eth_rx_queue_count(uint8_t port_id, uint16_t queue_id) > RTE_PMD_DEBUG_TRACE("Invalid port_id=%d\n", port_id); > return 0; > } > - RTE_ETH_FPTR_OR_ERR_RET(*dev->dev_ops->rx_queue_count, 0); > #endif > + RTE_ETH_FPTR_OR_ERR_RET(*dev->dev_ops->rx_queue_count, (uint32_t)-ENOTSUP); > + > return (*dev->dev_ops->rx_queue_count)(dev, queue_id); > } > > @@ -2525,6 +2528,7 @@ rte_eth_rx_queue_count(uint8_t port_id, uint16_t queue_id) > * - (1) if the specific DD bit is set. > * - (0) if the specific DD bit is not set. > * - (-ENODEV) if *port_id* invalid. > + * - (-ENOTSUP) if the device does not support this function > */ > static inline int > rte_eth_rx_descriptor_done(uint8_t port_id, uint16_t queue_id, uint16_t offset) > @@ -2536,8 +2540,8 @@ rte_eth_rx_descriptor_done(uint8_t port_id, uint16_t queue_id, uint16_t offset) > RTE_PMD_DEBUG_TRACE("Invalid port_id=%d\n", port_id); > return -ENODEV; > } > - RTE_ETH_FPTR_OR_ERR_RET(*dev->dev_ops->rx_descriptor_done, -ENOTSUP); > #endif > + RTE_ETH_FPTR_OR_ERR_RET(*dev->dev_ops->rx_descriptor_done, -ENOTSUP); > > return (*dev->dev_ops->rx_descriptor_done)( \ > dev->data->rx_queues[queue_id], offset); -- ____________________________________________________________________ |Roger B. Melton | | Cisco Systems | |CPP Software :|: :|: 7100 Kit Creek Rd | |+1.919.476.2332 phone :|||: :|||: RTP, NC 27709-4987 | |+1.919.392.1094 fax .:|||||||:..:|||||||:. rmelton@cisco.com | | | | This email may contain confidential and privileged material for the| | sole use of the intended recipient. Any review, use, distribution | | or disclosure by others is strictly prohibited. If you are not the | | intended recipient (or authorized to receive for the recipient), | | please contact the sender by reply email and delete all copies of | | this message. | | | | For corporate legal information go to: | | http://www.cisco.com/web/about/doing_business/legal/cri/index.html | |__________________________ http://www.cisco.com ____________________|