On Fri, Sep 02, 2022 at 03:58:53PM +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. Therefore, it should be better to
> move the definition of ftdi_sio_device to the end, remove
> create_sysfs_attrs and remove_sysfs_attrs, and convert to use dev_groups.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
This is not a "Fix:", sorry.
And did you test this change?
It does not work like the original submission did at all:
> Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
> ---
> Changelog:
>
> v1 -> v2:
>
> 1. Change the title.
> 2. Switch to use an attribute group.
> ---
> drivers/usb/serial/ftdi_sio.c | 124 ++++++++++++----------------------
> 1 file changed, 42 insertions(+), 82 deletions(-)
>
> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
> index d5a3986dfee7..41d8bfb02322 100644
> --- a/drivers/usb/serial/ftdi_sio.c
> +++ b/drivers/usb/serial/ftdi_sio.c
> @@ -1108,41 +1108,6 @@ 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);
>
> -static struct usb_serial_driver ftdi_sio_device = {
> - .driver = {
> - .owner = THIS_MODULE,
> - .name = "ftdi_sio",
> - },
> - .description = "FTDI USB Serial Device",
> - .id_table = id_table_combined,
> - .num_ports = 1,
> - .bulk_in_size = 512,
> - .bulk_out_size = 256,
> - .probe = ftdi_sio_probe,
> - .port_probe = ftdi_sio_port_probe,
> - .port_remove = ftdi_sio_port_remove,
> - .open = ftdi_open,
> - .dtr_rts = ftdi_dtr_rts,
> - .throttle = usb_serial_generic_throttle,
> - .unthrottle = usb_serial_generic_unthrottle,
> - .process_read_urb = ftdi_process_read_urb,
> - .prepare_write_buffer = ftdi_prepare_write_buffer,
> - .tiocmget = ftdi_tiocmget,
> - .tiocmset = ftdi_tiocmset,
> - .tiocmiwait = usb_serial_generic_tiocmiwait,
> - .get_icount = usb_serial_generic_get_icount,
> - .ioctl = ftdi_ioctl,
> - .get_serial = get_serial_info,
> - .set_serial = set_serial_info,
> - .set_termios = ftdi_set_termios,
> - .break_ctl = ftdi_break_ctl,
> - .tx_empty = ftdi_tx_empty,
> -};
> -
> -static struct usb_serial_driver * const serial_drivers[] = {
> - &ftdi_sio_device, NULL
> -};
No need to move this structure if you don't have to.
>
> #define WDR_TIMEOUT 5000 /* default urb timeout */
> #define WDR_SHORT_TIMEOUT 1000 /* shorter urb timeout */
> @@ -1729,50 +1694,12 @@ 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)
> -{
> - struct ftdi_private *priv = usb_get_serial_port_data(port);
> - int retval = 0;
> -
> - /* 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);
See how a specific file only gets added for a specific chip type? Your
change adds that file for all chip types.
That's not going to work. To solve this properly you need to set the
is_visible attribute in the attribute group and only create the needed
files based on the chip type.
thanks,
greg k-h
