> This actually breaks my machine. malloc() is saying allocation too
> large. OF_getproplen will return -1 on that. Is it possible that
> len is treated as uint64_t as it is an int and sizeof is effectively
> uint64_t?
Ah, yes; size_t is unsigned and wider than int on 64-bit platforms,
therefore int is converted to unsigned for the comparison. Casting
sizeof to int will do.
> Might be easier to have a check like:
>
> if (sc->sc_channels == NULL)
> return level < sc->sc_nlevels ? level : sc->sc_nlevels - 1;
>
> Then you don't need to indent the whole block. Makes the diff smaller
> and a bit easier to understand?
Sure; what about this new version, then?
Index: pwmbl.c
===================================================================
RCS file: /OpenBSD/src/sys/dev/fdt/pwmbl.c,v
retrieving revision 1.6
diff -u -p -r1.6 pwmbl.c
--- pwmbl.c 24 Oct 2021 17:52:26 -0000 1.6
+++ pwmbl.c 11 Nov 2022 06:46:41 -0000
@@ -35,7 +35,7 @@ struct pwmbl_softc {
struct device sc_dev;
uint32_t *sc_pwm;
int sc_pwm_len;
- uint32_t *sc_levels;
+ uint32_t *sc_levels; /* NULL if simple ramp */
int sc_nlevels;
uint32_t sc_max_level;
uint32_t sc_def_level;
@@ -73,7 +73,7 @@ pwmbl_attach(struct device *parent, stru
struct pwmbl_softc *sc = (struct pwmbl_softc *)self;
struct fdt_attach_args *faa = aux;
uint32_t *gpios;
- int i, len;
+ int len;
len = OF_getproplen(faa->fa_node, "pwms");
if (len < 0) {
@@ -95,7 +95,7 @@ pwmbl_attach(struct device *parent, stru
}
len = OF_getproplen(faa->fa_node, "brightness-levels");
- if (len > 0) {
+ if (len >= (int)sizeof(uint32_t)) {
sc->sc_levels = malloc(len, M_DEVBUF, M_WAITOK);
OF_getpropintarray(faa->fa_node, "brightness-levels",
sc->sc_levels, len);
@@ -107,13 +107,9 @@ pwmbl_attach(struct device *parent, stru
sc->sc_def_level = sc->sc_nlevels - 1;
sc->sc_def_level = sc->sc_levels[sc->sc_def_level];
} else {
+ /* No levels, assume a simple 0..255 ramp. */
sc->sc_nlevels = 256;
- sc->sc_levels = mallocarray(sc->sc_nlevels,
- sizeof(uint32_t), M_DEVBUF, M_WAITOK);
- for (i = 0; i < sc->sc_nlevels; i++)
- sc->sc_levels[i] = i;
- sc->sc_max_level = sc->sc_levels[sc->sc_nlevels - 1];
- sc->sc_def_level = sc->sc_levels[sc->sc_nlevels - 1];
+ sc->sc_max_level = sc->sc_def_level = sc->sc_nlevels - 1;
}
printf("\n");
@@ -143,6 +139,9 @@ pwmbl_find_brightness(struct pwmbl_softc
{
uint32_t mid;
int i;
+
+ if (sc->sc_levels == NULL)
+ return level < sc->sc_nlevels ? level : sc->sc_nlevels - 1;
for (i = 0; i < sc->sc_nlevels - 1; i++) {
mid = (sc->sc_levels[i] + sc->sc_levels[i + 1]) / 2;
