USB: handle bcd incrementation in usb modalias generation
This patch fixes a bug when incrementing/decrementing on a BCD formatted
integer (i.e. 0x09++ should be 0x10 not 0x0A). It just adds a function
for incrementing/decrementing BCD integers by converting to decimal,
doing the increment/decrement and then converting back to BCD.
Signed-off-by: Nathaniel McCallum <nathaniel@natemccallum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index e31f03a..6f426af 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -160,6 +160,45 @@
"MODULE_ALIAS(\"%s\");\n", alias);
}
+/* Handles increment/decrement of BCD formatted integers */
+/* Returns the previous value, so it works like i++ or i-- */
+static unsigned int incbcd(unsigned int *bcd,
+ int inc,
+ unsigned char max,
+ size_t chars)
+{
+ unsigned int init = *bcd, i, j;
+ unsigned long long c, dec = 0;
+
+ /* If bcd is not in BCD format, just increment */
+ if (max > 0x9) {
+ *bcd += inc;
+ return init;
+ }
+
+ /* Convert BCD to Decimal */
+ for (i=0 ; i < chars ; i++) {
+ c = (*bcd >> (i << 2)) & 0xf;
+ c = c > 9 ? 9 : c; /* force to bcd just in case */
+ for (j=0 ; j < i ; j++)
+ c = c * 10;
+ dec += c;
+ }
+
+ /* Do our increment/decrement */
+ dec += inc;
+ *bcd = 0;
+
+ /* Convert back to BCD */
+ for (i=0 ; i < chars ; i++) {
+ for (c=1,j=0 ; j < i ; j++)
+ c = c * 10;
+ c = (dec / c) % 10;
+ *bcd += c << (i << 2);
+ }
+ return init;
+}
+
static void do_usb_entry_multi(struct usb_device_id *id, struct module *mod)
{
unsigned int devlo, devhi;
@@ -208,10 +247,16 @@
}
if (clo > 0x0)
- do_usb_entry(id, devlo++, ndigits, clo, max, max, mod);
+ do_usb_entry(id,
+ incbcd(&devlo, 1, max,
+ sizeof(id->bcdDevice_lo) * 2),
+ ndigits, clo, max, max, mod);
if (chi < max)
- do_usb_entry(id, devhi--, ndigits, 0x0, chi, max, mod);
+ do_usb_entry(id,
+ incbcd(&devhi, -1, max,
+ sizeof(id->bcdDevice_lo) * 2),
+ ndigits, 0x0, chi, max, mod);
}
}