Certain devices such as Winbond Virtual Com Port, which is used in some usb printers, will stop responding after the usb_control_msg_send() calls in usb_set_interface(). These devices work fine without having usb_set_interface() called, so this flag prevents that call.
The naming is designed to mirror the existing USB_QUIRK_NO_SET_INTF flag, but that flag is not sufficient to make these devices work. Signed-off-by: Jeremy Figgins <[email protected]> --- drivers/usb/class/usblp.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c index 134dc2005ce9..6e2d58813d7d 100644 --- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -209,6 +209,7 @@ struct quirk_printer_struct { #define USBLP_QUIRK_BIDIR 0x1 /* reports bidir but requires unidirectional mode (no INs/reads) */ #define USBLP_QUIRK_USB_INIT 0x2 /* needs vendor USB init string */ #define USBLP_QUIRK_BAD_CLASS 0x4 /* descriptor uses vendor-specific Class or SubClass */ +#define USBLP_QUIRK_NO_SET_INTF 0x8 /* device can't handle Set-Interface requests */ static const struct quirk_printer_struct quirk_printers[] = { { 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */ @@ -227,6 +228,7 @@ static const struct quirk_printer_struct quirk_printers[] = { { 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <[email protected]> */ { 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */ { 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */ + { 0x0416, 0x5011, USBLP_QUIRK_NO_SET_INTF }, /* Winbond Electronics Corp. Virtual Com Port */ { 0, 0 } }; @@ -1332,7 +1334,11 @@ static int usblp_set_protocol(struct usblp *usblp, int protocol) alts = usblp->protocol[protocol].alt_setting; if (alts < 0) return -EINVAL; - r = usb_set_interface(usblp->dev, usblp->ifnum, alts); + if (usblp->quirks & USBLP_QUIRK_NO_SET_INTF) { + r = 0; + } else { + r = usb_set_interface(usblp->dev, usblp->ifnum, alts); + } if (r < 0) { printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n", alts, usblp->ifnum); -- 2.29.0
