From: Romain Izard <romain.izard.pro@xxxxxxxxx> When connecting a CDC-NCM gadget to an host that uses the NTP-32 mode, or that relies on the default CRC setting, the current implementation gets confused, and does not expect the correct signature for its packets. Fix this, by ensuring that the ndp_sign member in the f_ncm structure always contain a valid value. Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v4.19 --- Seems to have been forgotten when backporting NCM fixes. Needed to make Win10 accept Linux NCM gadget ethernet drivers/usb/gadget/function/f_ncm.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index b4571633f7b5..92a7c3a83945 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -36,9 +36,7 @@ /* to trigger crc/non-crc ndp signature */ -#define NCM_NDP_HDR_CRC_MASK 0x01000000 #define NCM_NDP_HDR_CRC 0x01000000 -#define NCM_NDP_HDR_NOCRC 0x00000000 enum ncm_notify_state { NCM_NOTIFY_NONE, /* don't notify */ @@ -530,6 +528,7 @@ static inline void ncm_reset_values(struct f_ncm *ncm) { ncm->parser_opts = &ndp16_opts; ncm->is_crc = false; + ncm->ndp_sign = ncm->parser_opts->ndp_sign; ncm->port.cdc_filter = DEFAULT_FILTER; /* doesn't make sense for ncm, fixed size used */ @@ -812,25 +811,20 @@ static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) | USB_CDC_SET_CRC_MODE: { - int ndp_hdr_crc = 0; - if (w_length != 0 || w_index != ncm->ctrl_id) goto invalid; switch (w_value) { case 0x0000: ncm->is_crc = false; - ndp_hdr_crc = NCM_NDP_HDR_NOCRC; DBG(cdev, "non-CRC mode selected\n"); break; case 0x0001: ncm->is_crc = true; - ndp_hdr_crc = NCM_NDP_HDR_CRC; DBG(cdev, "CRC mode selected\n"); break; default: goto invalid; } - ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc; value = 0; break; } @@ -847,6 +841,8 @@ static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) ctrl->bRequestType, ctrl->bRequest, w_value, w_index, w_length); } + ncm->ndp_sign = ncm->parser_opts->ndp_sign | + (ncm->is_crc ? NCM_NDP_HDR_CRC : 0); /* respond with data transfer or status phase? */ if (value >= 0) { -- 2.39.3