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-rw-r--r--drivers/usb/misc/chaoskey.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index 9aef46b3dfa8..6ddd08a32777 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -60,7 +60,8 @@ MODULE_LICENSE("GPL");
#define CHAOSKEY_BUF_LEN 64 /* max size of USB full speed packet */
-#define NAK_TIMEOUT (HZ) /* stall/wait timeout for device */
+#define NAK_TIMEOUT (HZ) /* normal stall/wait timeout */
+#define ALEA_FIRST_TIMEOUT (HZ*3) /* first stall/wait timeout for Alea */
#ifdef CONFIG_USB_DYNAMIC_MINORS
#define USB_CHAOSKEY_MINOR_BASE 0
@@ -88,6 +89,7 @@ struct chaoskey {
int open; /* open count */
bool present; /* device not disconnected */
bool reading; /* ongoing IO */
+ bool reads_started; /* track first read for Alea */
int size; /* size of buf */
int valid; /* bytes of buf read */
int used; /* bytes of buf consumed */
@@ -192,6 +194,9 @@ static int chaoskey_probe(struct usb_interface *interface,
dev->in_ep = in_ep;
+ if (udev->descriptor.idVendor != ALEA_VENDOR_ID)
+ dev->reads_started = 1;
+
dev->size = size;
dev->present = 1;
@@ -361,6 +366,7 @@ static int _chaoskey_fill(struct chaoskey *dev)
{
DEFINE_WAIT(wait);
int result;
+ bool started;
usb_dbg(dev->interface, "fill");
@@ -393,10 +399,17 @@ static int _chaoskey_fill(struct chaoskey *dev)
goto out;
}
+ /* The first read on the Alea takes a little under 2 seconds.
+ * Reads after the first read take only a few microseconds
+ * though. Presumably the entropy-generating circuit needs
+ * time to ramp up. So, we wait longer on the first read.
+ */
+ started = dev->reads_started;
+ dev->reads_started = true;
result = wait_event_interruptible_timeout(
dev->wait_q,
!dev->reading,
- NAK_TIMEOUT);
+ (started ? NAK_TIMEOUT : ALEA_FIRST_TIMEOUT) );
if (result < 0)
goto out;