rastor.c:302: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c: At top level: drivers/scsi/ultrastor.c:1202: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:1202: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c: In function 'ultrastor_queuecommand': drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:698: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:302: warning: matching constraint does not allow a register drivers/scsi/ultrastor.c:302: warning: matching constraint does not allow a register The following patch fixes it by using the '+' operator on the (*field) operand, marking it as read-write to gcc. I diffed the two resulting .s, and gcc produced the same code. This was tested with gcc 4.2.1 and gcc 3.4.3 Signed-off-by: Frederik Deweerdt Cc: Adrian Bunk Signed-off-by: James Bottomley )b