On Fri, Dec 23, 2016 at 09:22:29AM +0800, Even Xu wrote:
> +/**
> + * ishtp_cl_probe() - ISHTP client driver probe
> + * @cl_device: ISHTP client device instance
> + *
> + * This function gets called on device create on ISHTP bus
> + *
> + * Return: 0 on success, non zero on error
> + */
> +static int ishtp_cl_probe(struct ishtp_cl_device *cl_device)
> +{
> + struct ishtp_cl_miscdev *ishtp_cl_misc;
> + int ret;
> +
> + if (!cl_device)
> + return -ENODEV;
> +
> + ishtp_cl_misc = kzalloc(sizeof(struct ishtp_cl_miscdev),
> + GFP_KERNEL);
> + if (!ishtp_cl_misc)
> + return -ENOMEM;
> +
> + if (uuid_le_cmp(ishtp_smhi_guid,
> + cl_device->fw_client->props.protocol_name) == 0) {
> + ishtp_cl_misc->cl_miscdev.name = "ish-smhi";
> + } else if (uuid_le_cmp(ishtp_trace_guid,
> + cl_device->fw_client->props.protocol_name) == 0) {
> + ishtp_cl_misc->cl_miscdev.name = "ish-trace";
> + } else if (uuid_le_cmp(ishtp_traceconfig_guid,
> + cl_device->fw_client->props.protocol_name) == 0) {
> + ishtp_cl_misc->cl_miscdev.name = "ish-tracec";
> + } else if (uuid_le_cmp(ishtp_loader_guid,
> + cl_device->fw_client->props.protocol_name) == 0) {
> + ishtp_cl_misc->cl_miscdev.name = "ish-loader";
> + } else {
> + dev_err(&cl_device->dev, "Not supported client\n");
> + ret = -ENODEV;
> + goto release_mem;
> + }
> +
> + ishtp_cl_misc->cl_miscdev.parent = &cl_device->dev;
> + ishtp_cl_misc->cl_miscdev.fops = &ishtp_cl_fops;
> + ishtp_cl_misc->cl_miscdev.minor = MISC_DYNAMIC_MINOR,
> +
> + ret = misc_register(&ishtp_cl_misc->cl_miscdev);
> + if (ret) {
> + dev_err(&cl_device->dev, "misc device register failed\n");
> + goto release_mem;
> + }
Now your userspace device node is created and can be opened up and
accessed. But:
> +
> + ishtp_cl_misc->cl_device = cl_device;
> +
> + init_waitqueue_head(&ishtp_cl_misc->read_wait);
> +
> + ishtp_set_drvdata(cl_device, ishtp_cl_misc);
> +
> + ishtp_get_device(cl_device);
> +
> + mutex_init(&ishtp_cl_misc->cl_mutex);
> +
> + INIT_WORK(&ishtp_cl_misc->reset_work, ishtp_cl_reset_handler);
> +
> + /* Register event callback */
> + ishtp_register_event_cb(cl_device, ishtp_cl_event_cb);
You were not done setting up the device. What nasty races just
happened?
And the above functions can never fail? Why are you grabbing a refernce
to the cl_device yet doing nothing with it? That feels really broken
and wrong.
thanks,
greg k-h
