diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/misc/chaoskey.c | 17 |
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; |