Re: [PATCH v2 07/16] rpmsg: char: clean up rpmsg class

Arnaud POULIQUEN
2021-01-05T17:04:28Z

On 1/5/21 1:54 AM, Bjorn Andersson wrote:
> On Mon 04 Jan 18:47 CST 2021, Bjorn Andersson wrote:
>
>> On Tue 22 Dec 04:57 CST 2020, Arnaud Pouliquen wrote:
>>
>> This patch doesn't "clean up" the class, as described in $subject. It
>> just removes it.
>>
>>> Suppress the management of the rpmsg class as attribute. It is already
>>> handled in /sys/bus rpmsg as specified in
>>> documentation/ABI/testing/sysfs-bus-rpmsg.
>>
>> Afaict it doesn't relate to /sys/bus/rpmsg, but rather what attributes
>> should be associated with the rpmsg_device (and thereby present in its
>> sysfs directory). But if these attributes are also added by the bus,
>> then why do we have this code? If that's the case this seems like a nice
>> cleanup that we should do outside/before merging the other patches.
>>
>>> This patch prepares the migration of the control device in rpmsg_ctrl.
>>>
>>
>> It would be useful if the commit message described how it prepares for
>> the migration and why.
>>
>
> Now I see what this patch does, it removes the attributes from the
> character device's struct device, because they are provided by the
> struct rpmsg_device's bus!
>
> I wish your commit message made this obvious.
>
> Also, this implies that for a few patches here rpmsg_char is just
> broken - which I don't like.

I will move this patch at the end of the series and clarify commit message

Thanks
Arnaud

>
> Regards,
> Bjorn
>
>> Regards,
>> Bjorn
>>
>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>>> ---
>>> drivers/rpmsg/rpmsg_char.c | 48 --------------------------------------
>>> 1 file changed, 48 deletions(-)
>>>
>>> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
>>> index 4bbbacdbf3bb..732f5caf068a 100644
>>> --- a/drivers/rpmsg/rpmsg_char.c
>>> +++ b/drivers/rpmsg/rpmsg_char.c
>>> @@ -27,7 +27,6 @@
>>> #define RPMSG_DEV_MAX (MINORMASK + 1)
>>>
>>> static dev_t rpmsg_major;
>>> -static struct class *rpmsg_class;
>>>
>>> static DEFINE_IDA(rpmsg_ctrl_ida);
>>> static DEFINE_IDA(rpmsg_ept_ida);
>>> @@ -291,41 +290,6 @@ static const struct file_operations rpmsg_eptdev_fops = {
>>> .compat_ioctl = compat_ptr_ioctl,
>>> };
>>>
>>> -static ssize_t name_show(struct device *dev, struct device_attribute *attr,
>>> - char *buf)
>>> -{
>>> - struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
>>> -
>>> - return sprintf(buf, "%s\n", eptdev->chinfo.name);
>>> -}
>>> -static DEVICE_ATTR_RO(name);
>>> -
>>> -static ssize_t src_show(struct device *dev, struct device_attribute *attr,
>>> - char *buf)
>>> -{
>>> - struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
>>> -
>>> - return sprintf(buf, "%d\n", eptdev->chinfo.src);
>>> -}
>>> -static DEVICE_ATTR_RO(src);
>>> -
>>> -static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
>>> - char *buf)
>>> -{
>>> - struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
>>> -
>>> - return sprintf(buf, "%d\n", eptdev->chinfo.dst);
>>> -}
>>> -static DEVICE_ATTR_RO(dst);
>>> -
>>> -static struct attribute *rpmsg_eptdev_attrs[] = {
>>> - &dev_attr_name.attr,
>>> - &dev_attr_src.attr,
>>> - &dev_attr_dst.attr,
>>> - NULL
>>> -};
>>> -ATTRIBUTE_GROUPS(rpmsg_eptdev);
>>> -
>>> static void rpmsg_eptdev_release_device(struct device *dev)
>>> {
>>> struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
>>> @@ -358,9 +322,7 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
>>> init_waitqueue_head(&eptdev->readq);
>>>
>>> device_initialize(dev);
>>> - dev->class = rpmsg_class;
>>> dev->parent = &ctrldev->dev;
>>> - dev->groups = rpmsg_eptdev_groups;
>>> dev_set_drvdata(dev, eptdev);
>>>
>>> cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
>>> @@ -477,7 +439,6 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
>>> dev = &ctrldev->dev;
>>> device_initialize(dev);
>>> dev->parent = &rpdev->dev;
>>> - dev->class = rpmsg_class;
>>>
>>> cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
>>> ctrldev->cdev.owner = THIS_MODULE;
>>> @@ -553,17 +514,9 @@ static int rpmsg_char_init(void)
>>> return ret;
>>> }
>>>
>>> - rpmsg_class = class_create(THIS_MODULE, "rpmsg");
>>> - if (IS_ERR(rpmsg_class)) {
>>> - pr_err("failed to create rpmsg class\n");
>>> - unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>>> - return PTR_ERR(rpmsg_class);
>>> - }
>>> -
>>> ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
>>> if (ret < 0) {
>>> pr_err("rpmsgchr: failed to register rpmsg driver\n");
>>> - class_destroy(rpmsg_class);
>>> unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>>> }
>>>
>>> @@ -574,7 +527,6 @@ postcore_initcall(rpmsg_char_init);
>>> static void rpmsg_chrdev_exit(void)
>>> {
>>> unregister_rpmsg_driver(&rpmsg_chrdev_driver);
>>> - class_destroy(rpmsg_class);
>>> unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>>> }
>>> module_exit(rpmsg_chrdev_exit);
>>> --
>>> 2.17.1
>>>