driver/serial: remove return value of up_putc()
modify the prototype of up_putc(): remove the return value
The architecture code does not care about the return value of up_putc(), so removing it saves two statements:
Before: After:
de4c: e52de004 push {lr} @ (str lr, [sp, #-4]!) | de4c: e52de004 push {lr} @ (str lr, [sp, #-4]!)
de50: e24dd014 sub sp, sp, #20 | de50: e24dd014 sub sp, sp, #20
de54: e58d0004 str r0, [sp, #4] | de54: e58d0004 str r0, [sp, #4]
de58: e30030f8 movw r3, #248 @ 0xf8 | de58: e30030f8 movw r3, #248 @ 0xf8
de5c: e3423000 movt r3, #8192 @ 0x2000 | de5c: e3423000 movt r3, #8192 @ 0x2000
de60: e58d300c str r3, [sp, #12] | de60: e58d300c str r3, [sp, #12]
de64: e59d1004 ldr r1, [sp, #4] | de64: e59d1004 ldr r1, [sp, #4]
de68: e59d000c ldr r0, [sp, #12] | de68: e59d000c ldr r0, [sp, #12]
de6c: ebfffe66 bl d80c <pl011_putc> | de6c: ebfffe66 bl d80c <pl011_putc>
de70: e59d3004 ldr r3, [sp, #4] | de70: e28dd014 add sp, sp, #20
de74: e1a00003 mov r0, r3 | de74: e49df004 pop {pc} @ (ldr pc, [sp], #4)
de78: e28dd014 add sp, sp, #20 |
de7c: e49df004 pop {pc} @ (ldr pc, [sp], #4) |
Signed-off-by: chao an <anchao@lixiang.com>
c6591c0f49