[PATCH] staging: rtl8723bs: cast EEPROM_DEFAULT_DIFF to s8

[PATCH] staging: rtl8723bs: cast EEPROM_DEFAULT_DIFF to s8

[Ivy Lopez]

EEPROM_DEFAULT_DIFF is defined as the bare integer literal 0xFE
(254) but is only ever assigned into s8 (signed char) fields used
to store signed TX power calibration offsets. The implicit
truncation to -2 is intentional. BW20/BW40/CCK/OFDM_Diff fields
elsewhere in the same file already sign-extend 4-bit values into
8-bit signed offsets by hand, so -2 is consistent with that
existing pattern but the untyped macro doesn't communicate this,
and triggers -Wconversion at every one of its 8 use sites in
rtl8723b_hal_init.c.

Cast the macro to s8 at its definition so the sign truncation is
explicit and documented in one place instead of relying on implicit
conversion at each call site.

No functional change.

Signed-off-by: Ivy Lopez <skunkolee@gmail.com>
---
 drivers/staging/rtl8723bs/include/hal_pg.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8723bs/include/hal_pg.h b/drivers/staging/rtl8723bs/include/hal_pg.h
index 7cb9c441fc01..7f1f004ab817 100644
--- a/drivers/staging/rtl8723bs/include/hal_pg.h
+++ b/drivers/staging/rtl8723bs/include/hal_pg.h
@@ -40,7 +40,7 @@
 #define	EEPROM_RF_BT_SETTING_8723B		0xC3
 #define	EEPROM_VERSION_8723B			0xC4
 #define	EEPROM_CustomID_8723B			0xC5
-#define EEPROM_DEFAULT_DIFF			0XFE
+#define EEPROM_DEFAULT_DIFF			((s8)0XFE)
 
 /* RTL8723BS */
 #define	EEPROM_MAC_ADDR_8723BS			0x11A
-- 
2.55.0

Re: [PATCH] staging: rtl8723bs: cast EEPROM_DEFAULT_DIFF to s8

[Dan Carpenter]

On Sat, Aug 15, 2026 at 01:10:30PM -0600, Ivy Lopez wrote:
> EEPROM_DEFAULT_DIFF is defined as the bare integer literal 0xFE
> (254) but is only ever assigned into s8 (signed char) fields used
> to store signed TX power calibration offsets. The implicit
> truncation to -2 is intentional.

Just change it to:

#define EEPROM_DEFAULT_DIFF -2

regards,
dan carpenter

[PATCH v2] staging: rtl8723bs: define EEPROM_DEFAULT_DIFF as -2 directly

[Ivy Lopez]

EEPROM_DEFAULT_DIFF is defined as the bare integer literal 0xFE
(254) but is only ever assigned into s8 (signed char) fields used
to store signed TX power calibration offsets. The value -2 is the
intended default offset; expressing it as -2 directly instead of
0xFE avoids relying on implicit truncation of an unsigned-looking
hex literal into a signed field.

No functional change.

Signed-off-by: Ivy Lopez <skunkolee@gmail.com>
---
v2: express the value as -2 directly instead of casting 0xFE to s8,
    per Dan Carpenter's suggestion
---
 drivers/staging/rtl8723bs/include/hal_pg.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8723bs/include/hal_pg.h b/drivers/staging/rtl8723bs/include/hal_pg.h
index 7cb9c441fc01..83bf5f117e2d 100644
--- a/drivers/staging/rtl8723bs/include/hal_pg.h
+++ b/drivers/staging/rtl8723bs/include/hal_pg.h
@@ -40,7 +40,7 @@
 #define	EEPROM_RF_BT_SETTING_8723B		0xC3
 #define	EEPROM_VERSION_8723B			0xC4
 #define	EEPROM_CustomID_8723B			0xC5
-#define EEPROM_DEFAULT_DIFF			0XFE
+#define EEPROM_DEFAULT_DIFF			-2
 
 /* RTL8723BS */
 #define	EEPROM_MAC_ADDR_8723BS			0x11A
-- 
2.55.0