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new usb quirk: no-alt-set - won't even try set_conf or set_int_alt_set #1444

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Merged
michaelrsweet merged 4 commits into from
Dec 10, 2025
Merged

new usb quirk: no-alt-set - won't even try set_conf or set_int_alt_set #1444

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0625c39
new usb quirk: no-alt-set - won't even try set_conf or set_int_alt_set
snejok Dec 3, 2025
9871557
usb-quirks: enable no-alt-set for Samsung M337x 387x 407x Series
snejok Dec 3, 2025
d0038ef
No need extra debug printfs when NO_ALT_SET enabled
snejok Dec 5, 2025
84289ea
Fixed an annoying typo in the comments
snejok Dec 5, 2025
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2 changes: 1 addition & 1 deletion backend/org.cups.usb-quirks
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Original file line number Diff line number Diff line change
Expand Up @@ -208,7 +208,7 @@
0x04e8 0x344f whitelist

# Samsung M337x 387x 407x Series works without quirks
0x04e8 0x3460 whitelist
0x04e8 0x3460 whitelist no-alt-set

# Samsung ML-2160 Series (https://bugzilla.redhat.com/show_bug.cgi?id=873123)
0x04e8 0x330f unidir
Expand Down
13 changes: 10 additions & 3 deletions backend/usb-libusb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,9 @@ typedef struct usb_globals_s /* Global USB printer information */
#define USB_QUIRK_VENDOR_CLASS 0x0020 /* Descriptor uses vendor-specific
Class or SubClass */
#define USB_QUIRK_DELAY_CLOSE 0x0040 /* Delay close */
#define USB_QUIRK_NO_ALT_SET 0x0080 /* Some USB printers do not
like set_configuration and
set_interface */
#define USB_QUIRK_WHITELIST 0x0000 /* no quirks */


Expand Down Expand Up @@ -692,7 +695,8 @@ close_device(usb_printer_t *printer) /* I - Printer */
* If we have changed the configuration from one valid configuration
* to another, restore the old one
*/
if (printer->origconf > 0 && printer->origconf != number2)

if (printer->origconf > 0 && printer->origconf != number2 && !(printer->quirks & USB_QUIRK_NO_ALT_SET))
{
fprintf(stderr, "DEBUG: Restoring USB device configuration: %d -> %d\n",
number2, printer->origconf);
Expand Down Expand Up @@ -1339,6 +1343,9 @@ load_quirks(void)
if (strstr(line, " vendor-class"))
quirk->quirks |= USB_QUIRK_VENDOR_CLASS;

if (strstr(line, " no-alt-set"))
quirk->quirks |= USB_QUIRK_NO_ALT_SET;

cupsArrayAdd(all_quirks, quirk);
}

Expand Down Expand Up @@ -1597,7 +1604,7 @@ open_device(usb_printer_t *printer, /* I - Printer */
}
number1 = confptr->bConfigurationValue;

if (number1 != current)
if (number1 != current && !(printer->quirks & USB_QUIRK_NO_ALT_SET))
{
fprintf(stderr, "DEBUG: Switching USB device configuration: %d -> %d\n",
current, number1);
Expand Down Expand Up @@ -1649,7 +1656,7 @@ open_device(usb_printer_t *printer, /* I - Printer */
* printers (e.g., Samsung) don't like usb_set_altinterface.
*/

if (confptr->interface[printer->iface].num_altsetting > 1)
if (confptr->interface[printer->iface].num_altsetting > 1 && !(printer->quirks & USB_QUIRK_NO_ALT_SET))
{
number1 = confptr->interface[printer->iface].
altsetting[printer->altset].bInterfaceNumber;
Expand Down
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