The lookup helpers for dim-mode and ramp-ctl take a shortcut when
lookup_tbl is NULL: they accept any u32 value without range-checking
and return success unconditionally. Out-of-range values get silently
truncated by regmap_update_bits instead of triggering the dev_warn +
default-fallback path that the other properties use.

Add a field-width check for the NULL-table case so that values
exceeding the register field maximum are rejected the same way a
table-lookup miss is.

While here, also switch the error returns to -EINVAL for consistency.

Signed-off-by: Junjie Cao <[email protected]>
---
 drivers/video/backlight/aw99706.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/video/backlight/aw99706.c 
b/drivers/video/backlight/aw99706.c
index abacf5a6c8ae..a00a4144f160 100644
--- a/drivers/video/backlight/aw99706.c
+++ b/drivers/video/backlight/aw99706.c
@@ -94,6 +94,8 @@ static int aw99706_dt_property_lookup(const struct 
aw99706_dt_prop *prop,
        int i;
 
        if (!prop->lookup_tbl) {
+               if (dt_val > (prop->mask >> __ffs(prop->mask)))
+                       return -EINVAL;
                *val = dt_val;
                return 0;
        }
@@ -104,7 +106,7 @@ static int aw99706_dt_property_lookup(const struct 
aw99706_dt_prop *prop,
 
        *val = i;
 
-       return i == prop->tbl_size ? -1 : 0;
+       return i == prop->tbl_size ? -EINVAL : 0;
 }
 
 #define MIN_ILED_MAX   5000
@@ -116,11 +118,14 @@ aw99706_dt_property_iled_max_convert(const struct 
aw99706_dt_prop *prop,
                                     u32 dt_val, u8 *val)
 {
        if (dt_val > MAX_ILED_MAX || dt_val < MIN_ILED_MAX)
-               return -1;
+               return -EINVAL;
+
+       if ((dt_val - MIN_ILED_MAX) % STEP_ILED_MAX)
+               return -EINVAL;
 
        *val = (dt_val - MIN_ILED_MAX) / STEP_ILED_MAX;
 
-       return (dt_val - MIN_ILED_MAX) % STEP_ILED_MAX;
+       return 0;
 }
 
 static const struct aw99706_dt_prop aw99706_dt_props[] = {
-- 
2.43.0

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