On Mon 08 Nov 08:19 CST 2021, Arnaud Pouliquen wrote:
> Allows to probe the endpoint device on a remote name service announcement,
> by registering a rpmsg_driverfor the "rpmsg-raw" channel.
>
> With this patch the /dev/rpmsgX interface can be instantiated by the remote
> firmware.
>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
> ---
> drivers/rpmsg/rpmsg_char.c | 64 ++++++++++++++++++++++++++++++++++++++
> drivers/rpmsg/rpmsg_ctrl.c | 7 +++--
> 2 files changed, 69 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
> index 6a01e8e1c111..dd754c870ba1 100644
> --- a/drivers/rpmsg/rpmsg_char.c
> +++ b/drivers/rpmsg/rpmsg_char.c
> @@ -432,6 +432,58 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent
> }
> EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
>
> +static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
> +{
> + struct rpmsg_channel_info chinfo;
> + struct rpmsg_eptdev *eptdev;
> + struct device *dev = &rpdev->dev;
> +
> + memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
> + chinfo.src = rpdev->src;
> + chinfo.dst = rpdev->dst;
> +
> + eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, dev);
> + if (IS_ERR(eptdev))
> + return PTR_ERR(eptdev);
> +
> + /*
> + * Create the default endpoint associated to the rpmsg device and provide rpmsg_eptdev
> + * structure as callback private data.
> + * Do not allow the creation and release of an endpoint on /dev/rpmsgX open and close,
> + * reuse the default endpoint instead
> + */
> + eptdev->default_ept = rpmsg_create_default_ept(rpdev, rpmsg_ept_cb, eptdev, chinfo);
> + if (!eptdev->default_ept) {
> + dev_err(&rpdev->dev, "failed to create %s\n", chinfo.name);
> + put_device(dev);
Which get_device() does this correlate to?
> + kfree(eptdev);
After the device_initialize() in rpmsg_chrdev_eptdev_alloc() you're
supposed to put_device() &eptdev->dev, which would kfree(eptdev)...
Note though that rpmsg_eptdev_release_device() calls cdev_del(), which
you can't do. It was however recently reported that this cdev_del()
should be done in conjunction with the device_del() as the current
implementation enables a race between release and fops->open.
Regards,
Bjorn
> + return -EINVAL;
> + }
> +
> + return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
> +}
> +
> +static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
> +{
> + int ret;
> +
> + ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
> + if (ret)
> + dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
> +}
> +
> +static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
> + { .name = "rpmsg-raw" },
> + { },
> +};
> +
> +static struct rpmsg_driver rpmsg_chrdev_driver = {
> + .probe = rpmsg_chrdev_probe,
> + .remove = rpmsg_chrdev_remove,
> + .id_table = rpmsg_chrdev_id_table,
> + .drv.name = "rpmsg_chrdev",
> +};
> +
> static int rpmsg_chrdev_init(void)
> {
> int ret;
> @@ -442,12 +494,24 @@ static int rpmsg_chrdev_init(void)
> return ret;
> }
>
> + ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
> + if (ret < 0) {
> + pr_err("rpmsg: failed to register rpmsg raw driver\n");
> + goto free_region;
> + }
> +
> return 0;
> +
> +free_region:
> + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> +
> + return ret;
> }
> postcore_initcall(rpmsg_chrdev_init);
>
> static void rpmsg_chrdev_exit(void)
> {
> + unregister_rpmsg_driver(&rpmsg_chrdev_driver);
> unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> }
> module_exit(rpmsg_chrdev_exit);
> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
> index 59d2bd264fdb..298e75dc7774 100644
> --- a/drivers/rpmsg/rpmsg_ctrl.c
> +++ b/drivers/rpmsg/rpmsg_ctrl.c
> @@ -10,6 +10,9 @@
> * Based on rpmsg performance statistics driver by Michal Simek, which in turn
> * was based on TI & Google OMX rpmsg driver.
> */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> #include <linux/cdev.h>
> #include <linux/device.h>
> #include <linux/fs.h>
> @@ -193,13 +196,13 @@ static int rpmsg_ctrldev_init(void)
>
> ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
> if (ret < 0) {
> - pr_err("rpmsg: failed to allocate char dev region\n");
> + pr_err("failed to allocate char dev region\n");
> return ret;
> }
>
> ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
> if (ret < 0) {
> - pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
> + pr_err("failed to register rpmsg driver\n");
> unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> }
>
> --
> 2.17.1
>
