On Mar 28 2017 or thereabouts, Jason Gerecke wrote:
> The 'wacom_update_name' function is responsible for producing names for
> the input device nodes based on the hardware device name. Commit f2209d4
> added the ability to strip off prefixes like "Wacom Co.,Ltd." where the
> prefix was immediately (and redundantly) followed by "Wacom". The
> 2nd-generation Intuos Pro 2 has such a prefix, but with a small error
> (the period and comma are swapped) that prevents the existing code from
> matching it. We're loath to extend the number of cases out endlessly and
> so instead try to be smarter about name generation.
>
> We observe that the cause of the redundant prefixes is HID combining the
> manufacturer and product strings of USB devices together. By using the
> original product name (with "Wacom" prefixed, if it does not already
> exist in the string) we can bypass the gyrations to find and remove
> redundant prefixes. For devices connected by other busses, the problem
> either doesn't exist (e.g. BUS_BLUETOOTH) or the name should be replaced
> with a generic one entirely (e.g. BUS_I2C, BUS_INTEL_ISHTP).
Ouch. I hope Wacom doesn't plan on using BUS_INTEL_ISHTP for new devices
:)
>
> Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx>
> ---
> drivers/hid/wacom_sys.c | 65 +++++++++++++++++++++++++------------------------
> 1 file changed, 33 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
> index 037b9c04745a..ad5d8722fa84 100644
> --- a/drivers/hid/wacom_sys.c
> +++ b/drivers/hid/wacom_sys.c
> @@ -2026,41 +2026,42 @@ static void wacom_update_name(struct wacom *wacom, const char *suffix)
>
> /* Generic devices name unspecified */
> if ((features->type == HID_GENERIC) && !strcmp("Wacom HID", features->name)) {
> - if (strstr(wacom->hdev->name, "Wacom") ||
> - strstr(wacom->hdev->name, "wacom") ||
> - strstr(wacom->hdev->name, "WACOM")) {
> - /* name is in HID descriptor, use it */
> - strlcpy(name, wacom->hdev->name, sizeof(name));
> -
> - /* strip out excess whitespaces */
> - while (1) {
> - char *gap = strstr(name, " ");
> - if (gap == NULL)
> - break;
> - /* shift everything including the terminator */
> - memmove(gap, gap+1, strlen(gap));
> - }
> + char *product_name = NULL;
>
> - /* strip off excessive prefixing */
> - if (strstr(name, "Wacom Co.,Ltd. Wacom ") == name) {
> - int n = strlen(name);
> - int x = strlen("Wacom Co.,Ltd. ");
> - memmove(name, name+x, n-x+1);
> - }
> - if (strstr(name, "Wacom Co., Ltd. Wacom ") == name) {
> - int n = strlen(name);
> - int x = strlen("Wacom Co., Ltd. ");
> - memmove(name, name+x, n-x+1);
> - }
> + if (wacom->hdev->bus == BUS_USB) {
> + struct usb_interface *intf = to_usb_interface(wacom->hdev->dev.parent);
> + struct usb_device *dev = interface_to_usbdev(intf);
> + product_name = dev->product;
This will break uhid emulated devices in a very bad way (oops).
How about you either add a stub to get the product name from the
low-level driver, or simply add 2 pointers to strings to store the
product_name and the vendor_name in struct hid_device?
Bonus point if you let hid-core decide on the name based on the vendor
ID with a table of commonly used companies. hid-core could also clean up
the product name so you won't have to do it in each HID driver.
The choice of using a weird name for I2C devices was a lazy one from me,
and I am starting to hope for something better in the future.
Cheers,
Benjamin
> + }
> + else if (wacom->hdev->bus == BUS_BLUETOOTH) {
> + product_name = wacom->hdev->name;
> + }
>
> - /* get rid of trailing whitespace */
> - if (name[strlen(name)-1] == ' ')
> - name[strlen(name)-1] = '\0';
> - } else {
> - /* no meaningful name retrieved. use product ID */
> - snprintf(name, sizeof(name),
> - "%s %X", features->name, wacom->hdev->product);
> + if (!product_name) {
> + snprintf(name, sizeof(name), "%s %X",
> + features->name, wacom->hdev->product);
> }
> + else if (strstr(product_name, "Wacom") ||
> + strstr(product_name, "wacom") ||
> + strstr(product_name, "WACOM")) {
> + strlcpy(name, product_name, sizeof(name));
> + }
> + else {
> + snprintf(name, sizeof(name), "Wacom %s", product_name);
> + }
> +
> + /* strip out excess whitespaces */
> + while (1) {
> + char *gap = strstr(name, " ");
> + if (gap == NULL)
> + break;
> + /* shift everything including the terminator */
> + memmove(gap, gap+1, strlen(gap));
> + }
> +
> + /* get rid of trailing whitespace */
> + if (name[strlen(name)-1] == ' ')
> + name[strlen(name)-1] = '\0';
> } else {
> strlcpy(name, features->name, sizeof(name));
> }
> --
> 2.12.0
>
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