From: "Fredrik A Lindgren" <Fredrik.a.Lindgren@tietoevry.com>
To: "Van Haaren, Harry" <harry.van.haaren@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] Question: typedef of eventdev_info_get_t bug?
Date: Mon, 1 Feb 2021 10:02:16 +0000 [thread overview]
Message-ID: <VI1PR04MB4303A0A5649D8399667FB2DCC3B69@VI1PR04MB4303.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <BYAPR11MB3143A661523FD40B75A99BA5D7B69@BYAPR11MB3143.namprd11.prod.outlook.com>
Hi Harry,
You are correct, multiple structs with dev_infos_get defined in them caused me to jump to wrong implementation.
Still a bit "wrong" that comment for eventdev_info_get_t for event setup states returns 0 on success.
Using older version of https://github.com/Xilinx/dma_ip_drivers/tree/master/QDMA/DPDK targeting dpdk-19.11 for a corporate internal project as such can't give much details.
That version had a issue with no return statements in the infos_get function which was causing me issues.
Br,
Fredrik
-----Original Message-----
From: Van Haaren, Harry <harry.van.haaren@intel.com>
Sent: den 1 februari 2021 10:44
To: Fredrik A Lindgren <Fredrik.a.Lindgren@tieto.com>; dev@dpdk.org
Subject: RE: Question: typedef of eventdev_info_get_t bug?
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Fredrik A Lindgren
> Sent: Monday, February 1, 2021 9:22 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] Question: typedef of eventdev_info_get_t bug?
>
> While debugging a driver I was looking at the code and realized that
> eventdev_info_get_t typedef is defined with void return value but
> documentation for it says it should return 0
Hi Fredrik,
Be aware that your snippets of code below is mixing Event-dev and Eth-dev.
This is likely the cause of confusion.
> lib/librte_eventdev/eventdev_pmd.h:
>
> ...
> * @return
> * Returns 0 on success
> */
> typedef void (*eventdev_info_get_t)(struct rte_eventdev *dev,
> struct
> rte_event_dev_info *dev_info); ...
> struct rte_eventdev_ops {
> eventdev_info_get_t dev_infos_get; /**< Get device info. */
> ...
>
> While return value from it is used in lib/librte_ethdev/rte_ethdev.c:
>
> int
> rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info
> *dev_info) ...
> diag = (*dev->dev_ops->dev_infos_get)(dev, dev_info);
> if (diag != 0) {
> ...
At the Eventdev layer, info_get() can return int (particularly 0 on success, or -ERROR values).
At the Eventdev PMD layer, info_get() has a return void (the PMD cannot indicate failure on providing its info)
Hence, the info_get() typedef (for the PMD) is void, but the Eventdev layer itself checks some dev_id values etc, and can return -EINVAL or -ENOTSUP in case the PMD doesn't support info_get().
> Driver I'm debugging doesn't have any return statement in it's
> dev_infos_get function which seems to cause it to have "result" of
> last operation done in that function as return value.
> Though this behavior may be compiler specific but it should probably
> be clarified and updated (change prototype of stop using return value) to avoid issue with it.
Perhaps provide some more detail on Eventdev/Ethdev that you're debugging a driver on, provide some links to specific parts of the code? It seems like (from Eventdev anyway) its meant to work this way.
> Br,
> Fredrik
Regards, -Harry
next prev parent reply other threads:[~2021-02-01 10:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 9:21 Fredrik A Lindgren
2021-02-01 9:44 ` Van Haaren, Harry
2021-02-01 10:02 ` Fredrik A Lindgren [this message]
2021-02-01 10:31 ` Van Haaren, Harry
2021-02-01 12:49 ` Fredrik A Lindgren
2021-02-01 13:23 ` Van Haaren, Harry
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=VI1PR04MB4303A0A5649D8399667FB2DCC3B69@VI1PR04MB4303.eurprd04.prod.outlook.com \
--to=fredrik.a.lindgren@tietoevry.com \
--cc=dev@dpdk.org \
--cc=harry.van.haaren@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).