The hub_status_data function on the wireless USB root hub controller
(wusbhc_rh_status_data) always returns a positive value even if no ports
have changed. This patch updates wusbhc_rh_status_data to only return a
positive value if the root hub status needs to be queried. The current
implementation can also leave the upper bits of the port bitmap
uninitialized if wusbhc->ports_max is not one less than an even multiple
of 8. This patch fixes that as well by initializing the buffer to 0.
Signed-off-by: Thomas Pugliese <thomas.pugliese@xxxxxxxxx>
diff --git a/drivers/usb/wusbcore/rh.c b/drivers/usb/wusbcore/rh.c
index bdb0cc3..fe8bc77 100644
--- a/drivers/usb/wusbcore/rh.c
+++ b/drivers/usb/wusbcore/rh.c
@@ -141,18 +141,26 @@ static int wusbhc_rh_port_reset(struct wusbhc *wusbhc, u8 port_idx)
int wusbhc_rh_status_data(struct usb_hcd *usb_hcd, char *_buf)
{
struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
- size_t cnt, size;
- unsigned long *buf = (unsigned long *) _buf;
+ size_t cnt, size, bits_set = 0;
/* WE DON'T LOCK, see comment */
- size = wusbhc->ports_max + 1 /* hub bit */;
- size = (size + 8 - 1) / 8; /* round to bytes */
- for (cnt = 0; cnt < wusbhc->ports_max; cnt++)
- if (wusb_port_by_idx(wusbhc, cnt)->change)
- set_bit(cnt + 1, buf);
- else
- clear_bit(cnt + 1, buf);
- return size;
+ /* round up to bytes. Hub bit is bit 0 so add 1. */
+ size = DIV_ROUND_UP(wusbhc->ports_max + 1, 8);
+
+ /* clear the output buffer. */
+ memset(_buf, 0, size);
+ /* set the bit for each changed port. */
+ for (cnt = 0; cnt < wusbhc->ports_max; cnt++) {
+
+ if (wusb_port_by_idx(wusbhc, cnt)->change) {
+ const int bitpos = cnt+1;
+
+ _buf[bitpos/8] |= (1 << (bitpos % 8));
+ bits_set++;
+ }
+ }
+
+ return bits_set ? size : 0;
}
EXPORT_SYMBOL_GPL(wusbhc_rh_status_data);
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