This patch reduces the keepalive threshold of WUSB host controllers from
timeout/2 to timeout/3. The keepalive timer fires every timeout/2 ms, but
due to rounding errors and jitter, the host may decide not to send a
keepalive at timeout/2. By the time the next timer fires, a full timeout
period may have expired causing the device to be disconnected without ever
having been sent a keepalive. Changing the keepalive threshold to
timeout/3 ensures that at least one keepalive will be sent before a device
is disconnected. The patch also updates the code to use msecs_to_jiffies
consistently.
Signed-off-by: Thomas Pugliese <thomas.pugliese@xxxxxxxxx>
diff --git a/drivers/usb/wusbcore/devconnect.c b/drivers/usb/wusbcore/devconnect.c
index 1d36531..33a1278 100644
--- a/drivers/usb/wusbcore/devconnect.c
+++ b/drivers/usb/wusbcore/devconnect.c
@@ -455,8 +455,8 @@ static void __wusbhc_keep_alive(struct wusbhc *wusbhc)
dev_err(dev, "KEEPALIVE: device %u timed out\n",
wusb_dev->addr);
__wusbhc_dev_disconnect(wusbhc, wusb_port);
- } else if (time_after(jiffies, wusb_dev->entry_ts + tt/2)) {
- /* Approaching timeout cut out, need to refresh */
+ } else if (time_after(jiffies, wusb_dev->entry_ts + tt/3)) {
+ /* Approaching timeout cut off, need to refresh */
ie->bDeviceAddress[keep_alives++] = wusb_dev->addr;
}
}
@@ -1062,7 +1062,7 @@ int wusbhc_devconnect_start(struct wusbhc *wusbhc)
wusbhc->wuie_host_info = hi;
queue_delayed_work(wusbd, &wusbhc->keep_alive_timer,
- (wusbhc->trust_timeout*CONFIG_HZ)/1000/2);
+ msecs_to_jiffies(wusbhc->trust_timeout / 2));
return 0;
diff --git a/drivers/usb/wusbcore/wusbhc.c b/drivers/usb/wusbcore/wusbhc.c
index 0faca16..c35ee43 100644
--- a/drivers/usb/wusbcore/wusbhc.c
+++ b/drivers/usb/wusbcore/wusbhc.c
@@ -75,12 +75,11 @@ static ssize_t wusb_trust_timeout_store(struct device *dev,
result = -EINVAL;
goto out;
}
- /* FIXME: maybe we should check for range validity? */
- wusbhc->trust_timeout = trust_timeout;
+ wusbhc->trust_timeout = min_t(unsigned, trust_timeout, 500);
cancel_delayed_work(&wusbhc->keep_alive_timer);
flush_workqueue(wusbd);
queue_delayed_work(wusbd, &wusbhc->keep_alive_timer,
- (trust_timeout * CONFIG_HZ)/1000/2);
+ msecs_to_jiffies(wusbhc->trust_timeout / 2));
out:
return result < 0 ? result : size;
}
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