MFC r305345:

With clang 3.9.0, compiling ppbus(4) results in the following warnings:

sys/dev/ppbus/ppb_1284.c:296:46: error: implicit conversion from 'int'
to 'char' changes value from 144 to -112 [-Werror,-Wconstant-conversion]
	if ((error = do_peripheral_wait(bus, SELECT | nBUSY, 0))) {
		     ~~~~~~~~~~~~~~~~~~      ~~~~~~~^~~~~~~
sys/dev/ppbus/ppb_1284.c:785:48: error: implicit conversion from 'int'
to 'char' changes value from 240 to -16 [-Werror,-Wconstant-conversion]
		if (do_1284_wait(bus, nACK | SELECT | PERROR | nBUSY,
		    ~~~~~~~~~~~~      ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
sys/dev/ppbus/ppb_1284.c:786:29: error: implicit conversion from 'int'
to 'char' changes value from 240 to -16 [-Werror,-Wconstant-conversion]
					nACK | SELECT | PERROR | nBUSY)) {
					~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~

This is because nBUSY is 0x80, so the plain char argument is wrapped to
a negative value.  Fix this in a minimal fashion, by using uint8_t in a
few places.

Reviewed by:	emaste
Differential Revision: https://reviews.freebsd.org/D7771

3 files changed, 6 insertions, 6 deletions

diff --git a/sys/dev/ppbus/ppb_1284.c b/sys/dev/ppbus/ppb_1284.c
index 31f38ce..5e86977 100644
--- a/sys/dev/ppbus/ppb_1284.c
+++ b/sys/dev/ppbus/ppb_1284.c
@@ -57,13 +57,13 @@ __FBSDID("$FreeBSD$");
  * Wait for the peripherial up to 40ms
  */
 static int
-do_1284_wait(device_t bus, char mask, char status)
+do_1284_wait(device_t bus, uint8_t mask, uint8_t status)
 {
 	return (ppb_poll_bus(bus, 4, mask, status, PPB_NOINTR | PPB_POLL));
 }
 
 static int
-do_peripheral_wait(device_t bus, char mask, char status)
+do_peripheral_wait(device_t bus, uint8_t mask, uint8_t status)
 {
 	return (ppb_poll_bus(bus, 100, mask, status, PPB_NOINTR | PPB_POLL));
 }
diff --git a/sys/dev/ppbus/ppb_base.c b/sys/dev/ppbus/ppb_base.c
index 256d7a4..b87b597 100644
--- a/sys/dev/ppbus/ppb_base.c
+++ b/sys/dev/ppbus/ppb_base.c
@@ -54,11 +54,11 @@ MODULE_VERSION(ppbus, 1);
  */
 int
 ppb_poll_bus(device_t bus, int max,
-	     char mask, char status, int how)
+	     uint8_t mask, uint8_t status, int how)
 {
 	struct ppb_data *ppb = DEVTOSOFTC(bus);
 	int i, j, error;
-	char r;
+	uint8_t r;
 
 	ppb_assert_locked(bus);
 
@@ -186,7 +186,7 @@ ppb_ecp_sync(device_t bus)
 int
 ppb_get_status(device_t bus, struct ppb_status *status)
 {
-	register char r;
+	uint8_t r;
 
 	ppb_assert_locked(bus);
 
diff --git a/sys/dev/ppbus/ppbconf.h b/sys/dev/ppbus/ppbconf.h
index c898482..8ac578e 100644
--- a/sys/dev/ppbus/ppbconf.h
+++ b/sys/dev/ppbus/ppbconf.h
@@ -263,7 +263,7 @@ extern void _ppb_assert_locked(device_t, const char *, int);
 extern void ppb_init_callout(device_t, struct callout *, int);
 extern int ppb_sleep(device_t, void *, int, const char *, int);
 extern int ppb_get_status(device_t, struct ppb_status *);
-extern int ppb_poll_bus(device_t, int, char, char, int);
+extern int ppb_poll_bus(device_t, int, uint8_t, uint8_t, int);
 extern int ppb_reset_epp_timeout(device_t);
 extern int ppb_ecp_sync(device_t);
 extern int ppb_get_epp_protocol(device_t);