101 /* SOF, ADDR, CTRL, LEN1, LEN2, ..., FCS, EOF */
293 	u8 fcs;  member
463  *	gsm_fcs_add	-	update FCS
464  *	@fcs: Current FCS
467  *	Update the FCS to include c. Uses the algorithm in the specification
471 static inline u8 gsm_fcs_add(u8 fcs, u8 c)  in gsm_fcs_add()  argument
473 	return gsm_fcs8[fcs ^ c];  in gsm_fcs_add()
477  *	gsm_fcs_add_block	-	update FCS for a block
478  *	@fcs: Current FCS
482  *	Update the FCS to include c. Uses the algorithm in the specification
486 static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len)  in gsm_fcs_add_block()  argument
489 		fcs = gsm_fcs8[fcs ^ *c++];  in gsm_fcs_add_block()
490 	return fcs;  in gsm_fcs_add_block()
904 #define HDR_LEN		6	/* ADDR CTRL [LEN.2] DATA FCS */
910  *	@len: length excluding header and FCS
925 	m->data = m->buffer + HDR_LEN - 1;	/* Allow for FCS */  in gsm_data_alloc()
1095 	u8 *fcs = dp + msg->len;  in __gsm_data_queue()  local
1112 	*fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp);  in __gsm_data_queue()
1115 		*fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len);  in __gsm_data_queue()
1116 	*fcs = 0xFF - *fcs;  in __gsm_data_queue()
1121 	/* Move the header back and adjust the length, also allow for the FCS  in __gsm_data_queue()
2750  *	The fcs holds the header FCS but any data FCS must be added here.
2759 	if (gsm->fcs != GOOD_FCS) {  in gsm_queue()
2762 			pr_debug("BAD FCS %02x\n", gsm->fcs);  in gsm_queue()
2868 			gsm->fcs = INIT_FCS;  in gsm0_receive()
2872 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm0_receive()
2877 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm0_receive()
2882 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm0_receive()
2899 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm0_receive()
2916 			/* Calculate final FCS for UI frames over all data */  in gsm0_receive()
2918 				gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf,  in gsm0_receive()
2924 	case GSM_FCS:		/* FCS follows the packet */  in gsm0_receive()
2925 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm0_receive()
2970 			/* Remove the FCS from data */  in gsm1_receive()
2973 				/* Calculate final FCS for UI frames over all  in gsm1_receive()
2974 				 * data but FCS  in gsm1_receive()
2976 				gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf,  in gsm1_receive()
2979 			/* Add the FCS itself to test against GOOD_FCS */  in gsm1_receive()
2980 			gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]);  in gsm1_receive()
3014 		gsm->fcs = INIT_FCS;  in gsm1_receive()
3017 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm1_receive()
3022 		gsm->fcs = gsm_fcs_add(gsm->fcs, c);  in gsm1_receive()
3028 		if (gsm->count > gsm->mru) {	/* Allow one for the FCS */  in gsm1_receive()