| Message ID | 20220914071334.2820756-1-jiasheng@iscas.ac.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5] USB: serial: ftdi_sio: Convert to use dev_groups | expand |
On Wed, Sep 14, 2022 at 03:13:34PM +0800, Jiasheng Jiang wrote: > The driver core supports the ability to handle the creation and removal > of device-specific sysfs files in a race-free manner. > Moreover, it can > guarantee the success of creation. I don't believe this is true, driver core just handles the errors. > Therefore, it should be better to > convert to use dev_groups. > Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> > --- > Changelog: > > v4 -> v5: > > 1. Use a forward declaration for ftdi_sio_groups. > 2. Correct ftdi_sio_attr_is_visible() implementation. > > v3 -> v4: > > 1. Move the code and remove the pre-definitions. > > v2 -> v3: > > 1. Add is_visible to filter the unneeded files. > > v1 -> v2: > > 1. Change the title. > 2. Switch to use an attribute group. > --- > drivers/usb/serial/ftdi_sio.c | 60 +++++++++++++++++------------------ > 1 file changed, 29 insertions(+), 31 deletions(-) > > diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c > index d5a3986dfee7..660181064cda 100644 > --- a/drivers/usb/serial/ftdi_sio.c > +++ b/drivers/usb/serial/ftdi_sio.c > @@ -1108,10 +1108,13 @@ static u32 ftdi_232bm_baud_to_divisor(int baud); > static u32 ftdi_2232h_baud_base_to_divisor(int baud, int base); > static u32 ftdi_2232h_baud_to_divisor(int baud); > > +extern const struct attribute_group *ftdi_sio_groups[]; Why did you use extern here? Should be static. > + > static struct usb_serial_driver ftdi_sio_device = { > .driver = { > .owner = THIS_MODULE, > .name = "ftdi_sio", > + .dev_groups = ftdi_sio_groups, > }, > .description = "FTDI USB Serial Device", > .id_table = id_table_combined, > @@ -1729,38 +1732,19 @@ static ssize_t event_char_store(struct device *dev, > } > static DEVICE_ATTR_WO(event_char); > > -static int create_sysfs_attrs(struct usb_serial_port *port) > +static umode_t ftdi_sio_attr_is_visible(struct kobject *kobj, > + struct attribute *attr, int idx) I'd drop the "sio" infix from all of these new symbols and just call this one ftdi_is_visible(). > { > + struct device *dev = kobj_to_dev(kobj); > + struct usb_serial_port *port = container_of(dev, struct usb_serial_port, dev); > struct ftdi_private *priv = usb_get_serial_port_data(port); > - int retval = 0; > + umode_t mode = attr->mode; > > /* XXX I've no idea if the original SIO supports the event_char > * sysfs parameter, so I'm playing it safe. */ > if (priv->chip_type != SIO) { > - dev_dbg(&port->dev, "sysfs attributes for %s\n", ftdi_chip_name[priv->chip_type]); > - retval = device_create_file(&port->dev, &dev_attr_event_char); > - if ((!retval) && > - (priv->chip_type == FT232BM || > - priv->chip_type == FT2232C || > - priv->chip_type == FT232RL || > - priv->chip_type == FT2232H || > - priv->chip_type == FT4232H || > - priv->chip_type == FT232H || > - priv->chip_type == FTX)) { > - retval = device_create_file(&port->dev, > - &dev_attr_latency_timer); > - } > - } > - return retval; > -} > - > -static void remove_sysfs_attrs(struct usb_serial_port *port) > -{ > - struct ftdi_private *priv = usb_get_serial_port_data(port); > - > - /* XXX see create_sysfs_attrs */ > - if (priv->chip_type != SIO) { > - device_remove_file(&port->dev, &dev_attr_event_char); > + if (attr == &dev_attr_event_char.attr) > + return mode; > if (priv->chip_type == FT232BM || > priv->chip_type == FT2232C || > priv->chip_type == FT232RL || > @@ -1768,12 +1752,29 @@ static void remove_sysfs_attrs(struct usb_serial_port *port) > priv->chip_type == FT4232H || > priv->chip_type == FT232H || > priv->chip_type == FTX) { > - device_remove_file(&port->dev, &dev_attr_latency_timer); > + if (attr == &dev_attr_latency_timer.attr) > + return mode; > } > } > - > + return 0; > } > > +static struct attribute *ftdi_sio_attrs[] = { > + &dev_attr_event_char.attr, > + &dev_attr_latency_timer.attr, > + NULL, nit: no need for comma after NULL. > +}; > + > +static const struct attribute_group ftdi_sio_group = { > + .attrs = ftdi_sio_attrs, > + .is_visible = ftdi_sio_attr_is_visible, > +}; > + > +const struct attribute_group *ftdi_sio_groups[] = { Missing static. > + &ftdi_sio_group, > + NULL > +}; > + > #ifdef CONFIG_GPIOLIB > > static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode) > @@ -2251,7 +2252,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port) > if (read_latency_timer(port) < 0) > priv->latency = 16; > write_latency_timer(port); > - create_sysfs_attrs(port); > > result = ftdi_gpio_init(port); > if (result < 0) { > @@ -2377,8 +2377,6 @@ static void ftdi_sio_port_remove(struct usb_serial_port *port) > > ftdi_gpio_remove(port); > > - remove_sysfs_attrs(port); > - > kfree(priv); > } But in general this looks good now. There has been some recent changes to how this driver handles device types so I rebased this patch on top, fixed up the above and amended the commit message. The result is here: https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial.git/commit/?h=usb-next&id=0f6632e2e8beb6a1e0895c1309dd0b84b805c202 Thanks. Johan
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index d5a3986dfee7..660181064cda 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1108,10 +1108,13 @@ static u32 ftdi_232bm_baud_to_divisor(int baud); static u32 ftdi_2232h_baud_base_to_divisor(int baud, int base); static u32 ftdi_2232h_baud_to_divisor(int baud); +extern const struct attribute_group *ftdi_sio_groups[]; + static struct usb_serial_driver ftdi_sio_device = { .driver = { .owner = THIS_MODULE, .name = "ftdi_sio", + .dev_groups = ftdi_sio_groups, }, .description = "FTDI USB Serial Device", .id_table = id_table_combined, @@ -1729,38 +1732,19 @@ static ssize_t event_char_store(struct device *dev, } static DEVICE_ATTR_WO(event_char); -static int create_sysfs_attrs(struct usb_serial_port *port) +static umode_t ftdi_sio_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int idx) { + struct device *dev = kobj_to_dev(kobj); + struct usb_serial_port *port = container_of(dev, struct usb_serial_port, dev); struct ftdi_private *priv = usb_get_serial_port_data(port); - int retval = 0; + umode_t mode = attr->mode; /* XXX I've no idea if the original SIO supports the event_char * sysfs parameter, so I'm playing it safe. */ if (priv->chip_type != SIO) { - dev_dbg(&port->dev, "sysfs attributes for %s\n", ftdi_chip_name[priv->chip_type]); - retval = device_create_file(&port->dev, &dev_attr_event_char); - if ((!retval) && - (priv->chip_type == FT232BM || - priv->chip_type == FT2232C || - priv->chip_type == FT232RL || - priv->chip_type == FT2232H || - priv->chip_type == FT4232H || - priv->chip_type == FT232H || - priv->chip_type == FTX)) { - retval = device_create_file(&port->dev, - &dev_attr_latency_timer); - } - } - return retval; -} - -static void remove_sysfs_attrs(struct usb_serial_port *port) -{ - struct ftdi_private *priv = usb_get_serial_port_data(port); - - /* XXX see create_sysfs_attrs */ - if (priv->chip_type != SIO) { - device_remove_file(&port->dev, &dev_attr_event_char); + if (attr == &dev_attr_event_char.attr) + return mode; if (priv->chip_type == FT232BM || priv->chip_type == FT2232C || priv->chip_type == FT232RL || @@ -1768,12 +1752,29 @@ static void remove_sysfs_attrs(struct usb_serial_port *port) priv->chip_type == FT4232H || priv->chip_type == FT232H || priv->chip_type == FTX) { - device_remove_file(&port->dev, &dev_attr_latency_timer); + if (attr == &dev_attr_latency_timer.attr) + return mode; } } - + return 0; } +static struct attribute *ftdi_sio_attrs[] = { + &dev_attr_event_char.attr, + &dev_attr_latency_timer.attr, + NULL, +}; + +static const struct attribute_group ftdi_sio_group = { + .attrs = ftdi_sio_attrs, + .is_visible = ftdi_sio_attr_is_visible, +}; + +const struct attribute_group *ftdi_sio_groups[] = { + &ftdi_sio_group, + NULL +}; + #ifdef CONFIG_GPIOLIB static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode) @@ -2251,7 +2252,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port) if (read_latency_timer(port) < 0) priv->latency = 16; write_latency_timer(port); - create_sysfs_attrs(port); result = ftdi_gpio_init(port); if (result < 0) { @@ -2377,8 +2377,6 @@ static void ftdi_sio_port_remove(struct usb_serial_port *port) ftdi_gpio_remove(port); - remove_sysfs_attrs(port); - kfree(priv); }
The driver core supports the ability to handle the creation and removal of device-specific sysfs files in a race-free manner. Moreover, it can guarantee the success of creation. Therefore, it should be better to convert to use dev_groups. Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> --- Changelog: v4 -> v5: 1. Use a forward declaration for ftdi_sio_groups. 2. Correct ftdi_sio_attr_is_visible() implementation. v3 -> v4: 1. Move the code and remove the pre-definitions. v2 -> v3: 1. Add is_visible to filter the unneeded files. v1 -> v2: 1. Change the title. 2. Switch to use an attribute group. --- drivers/usb/serial/ftdi_sio.c | 60 +++++++++++++++++------------------ 1 file changed, 29 insertions(+), 31 deletions(-)