[PATCH 29/33] serial: 8250: drop DEBUG_AUTOCONF() macro

Jiri Slaby (SUSE)
2025-06-11T10:04:15Z

DEBUG_AUTOCONF() is always disabled (by "#if 0"), so one would need to
recompile the kernel to use it. And even if they did, they would find
out it is broken anyway:
error: variable 'scratch' is used uninitialized whenever 'if' condition is false

Drop it.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
drivers/tty/serial/8250/8250_port.c | 39 ++---------------------------
1 file changed, 2 insertions(+), 37 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 6363915a1787..e93bfdac3d0e 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -38,15 +38,6 @@

#include "8250.h"

-/*
- * Debugging.
- */
-#if 0
-#define DEBUG_AUTOCONF(fmt...) printk(fmt)
-#else
-#define DEBUG_AUTOCONF(fmt...) do { } while (0)
-#endif
-
/*
* Here we define the default xmit fifo size used for each type of UART.
*/
@@ -825,8 +816,6 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
id3 = serial_icr_read(up, UART_ID3);
rev = serial_icr_read(up, UART_REV);

- DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
-
if (id1 == 0x16 && id2 == 0xC9 &&
(id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
up->port.type = PORT_16C950;
@@ -850,7 +839,6 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
* 0x14 - XR16C854.
*/
id1 = autoconfig_read_divisor_id(up);
- DEBUG_AUTOCONF("850id=%04x ", id1);

id2 = id1 >> 8;
if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
@@ -937,7 +925,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)
if (serial_in(up, UART_EFR) == 0) {
serial_out(up, UART_EFR, 0xA8);
if (serial_in(up, UART_EFR) != 0) {
- DEBUG_AUTOCONF("EFRv1 ");
up->port.type = PORT_16650;
up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
} else {
@@ -950,8 +937,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)

if (status1 == UART_IIR_FIFO_ENABLED_16750)
up->port.type = PORT_16550A_FSL64;
- else
- DEBUG_AUTOCONF("Motorola 8xxx DUART ");
}
serial_out(up, UART_EFR, 0);
return;
@@ -963,7 +948,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)
*/
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
- DEBUG_AUTOCONF("EFRv2 ");
autoconfig_has_efr(up);
return;
}
@@ -1026,8 +1010,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)

serial_out(up, UART_LCR, 0);

- DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
-
if (status1 == UART_IIR_FIFO_ENABLED_16550A &&
status2 == UART_IIR_FIFO_ENABLED_16750) {
up->port.type = PORT_16750;
@@ -1056,17 +1038,10 @@ static void autoconfig_16550a(struct uart_8250_port *up)
* It's an Xscale.
* We'll leave the UART_IER_UUE bit set to 1 (enabled).
*/
- DEBUG_AUTOCONF("Xscale ");
up->port.type = PORT_XSCALE;
up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
return;
}
- } else {
- /*
- * If we got here we couldn't force the IER_UUE bit to 0.
- * Log it and continue.
- */
- DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
}
serial_out(up, UART_IER, iersave);

@@ -1098,9 +1073,6 @@ static void autoconfig(struct uart_8250_port *up)
if (!port->iobase && !port->mapbase && !port->membase)
return;

- DEBUG_AUTOCONF("%s: autoconf (0x%04lx, 0x%p): ",
- port->name, port->iobase, port->membase);
-
/*
* We really do need global IRQs disabled here - we're going to
* be frobbing the chips IRQ enable register to see if it exists.
@@ -1147,9 +1119,7 @@ static void autoconfig(struct uart_8250_port *up)
* We failed; there's nothing here
*/
uart_port_unlock_irqrestore(port, flags);
- DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
- scratch2, scratch3);
- goto out;
+ return;
}
}

@@ -1171,9 +1141,7 @@ static void autoconfig(struct uart_8250_port *up)
serial8250_out_MCR(up, save_mcr);
if (status1 != (UART_MSR_DCD | UART_MSR_CTS)) {
uart_port_unlock_irqrestore(port, flags);
- DEBUG_AUTOCONF("LOOP test failed (%02x) ",
- status1);
- goto out;
+ return;
}
}

@@ -1241,9 +1209,6 @@ static void autoconfig(struct uart_8250_port *up)
dev_warn(port->dev, "detected caps %08x should be %08x\n",
old_capabilities, up->capabilities);
}
-out:
- DEBUG_AUTOCONF("iir=%d ", scratch);
- DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name);
}

static void autoconfig_irq(struct uart_8250_port *up)
--
2.49.0