From 078f7f47392b4cb502e6ea021495ef427f4e3dc7 Mon Sep 17 00:00:00 2001
From: Con Kolivas <kernel@kolivas.org>
Date: Tue, 8 Oct 2013 23:15:15 +1100
Subject: [PATCH] Check return values when attempting to open a BF1 device and
 set the msg size as a macro.

---
 driver-bitfury.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/driver-bitfury.c b/driver-bitfury.c
index c1e3124d..df87e9e4 100644
--- a/driver-bitfury.c
+++ b/driver-bitfury.c
@@ -15,6 +15,7 @@
 
 /* Wait longer 1/3 longer than it would take for a full nonce range */
 #define BF1WAIT 1600
+#define BF1MSGSIZE 7
 
 static void bitfury_empty_buffer(struct cgpu_info *bitfury)
 {
@@ -26,18 +27,29 @@ static void bitfury_empty_buffer(struct cgpu_info *bitfury)
 	} while (amount);
 }
 
-static void bitfury_open(struct cgpu_info *bitfury)
+static int bitfury_open(struct cgpu_info *bitfury)
 {
 	uint32_t buf[2];
+	int err;
 
 	bitfury_empty_buffer(bitfury);
 	/* Magic sequence to reset device only really needed for windows but
 	 * harmless on linux. */
 	buf[0] = 0x80250000;
 	buf[1] = 0x00000800;
-	usb_transfer(bitfury, 0, 9, 1, 0, C_BF1_RESET);
-	usb_transfer(bitfury, 0x21, 0x22, 0, 0, C_BF1_OPEN);
-	usb_transfer_data(bitfury, 0x21, 0x20, 0x0000, 0, buf, 7, C_BF1_INIT);
+	err = usb_transfer(bitfury, 0, 9, 1, 0, C_BF1_RESET);
+	if (!err)
+		err = usb_transfer(bitfury, 0x21, 0x22, 0, 0, C_BF1_OPEN);
+	if (!err) {
+		err = usb_transfer_data(bitfury, 0x21, 0x20, 0x0000, 0, buf,
+					BF1MSGSIZE, C_BF1_INIT);
+	}
+
+	if (err < 0) {
+		applog(LOG_INFO, "%s %d: Failed to open with error %s", bitfury->drv->name,
+		       bitfury->device_id, libusb_error_name(err));
+	}
+	return (err == BF1MSGSIZE);
 }
 
 static void bitfury_close(struct cgpu_info *bitfury)
@@ -95,15 +107,16 @@ static bool bitfury_reset(struct cgpu_info *bitfury)
 		       bitfury->drv->name, bitfury->device_id);
 		return false;
 	}
-	err = usb_read_timeout(bitfury, buf, 7, &amount, BF1WAIT, C_BF1_GETRESET);
+	err = usb_read_timeout(bitfury, buf, BF1MSGSIZE, &amount, BF1WAIT,
+			       C_BF1_GETRESET);
 	if (err) {
 		applog(LOG_INFO, "%s %d: Failed to read GETRESET",
 		       bitfury->drv->name, bitfury->device_id);
 		return false;
 	}
-	if (amount != 7) {
-		applog(LOG_INFO, "%s %d: Getreset received %d bytes instead of 7",
-		       bitfury->drv->name, bitfury->device_id, amount);
+	if (amount != BF1MSGSIZE) {
+		applog(LOG_INFO, "%s %d: Getreset received %d bytes instead of %d",
+		       bitfury->drv->name, bitfury->device_id, amount, BF1MSGSIZE);
 		return false;
 	}
 	applog(LOG_DEBUG, "%s %d: Getreset returned %s", bitfury->drv->name,
@@ -131,7 +144,8 @@ static bool bitfury_detect_one(struct libusb_device *dev, struct usb_find_device
 
 	usb_buffer_enable(bitfury);
 
-	bitfury_open(bitfury);
+	if (!bitfury_open(bitfury))
+		goto out_close;
 
 	/* Send getinfo request */
 	if (!bitfury_getinfo(bitfury, info))
@@ -235,7 +249,8 @@ static int64_t bitfury_scanhash(struct thr_info *thr, struct work *work,
 	ms_diff = BF1WAIT - ms_tdiff(&tv_now, &info->tv_start);
 	if (unlikely(ms_diff < 10))
 		ms_diff = 10;
-	usb_read_once_timeout(bitfury, info->buf + info->tot, 7, &amount, ms_diff, C_BF1_GETRES);
+	usb_read_once_timeout(bitfury, info->buf + info->tot, BF1MSGSIZE,
+			      &amount, ms_diff, C_BF1_GETRES);
 	info->tot += amount;
 	while (amount) {
 		usb_read_once_timeout(bitfury, info->buf + info->tot, 512, &amount, 10, C_BF1_GETRES);
@@ -249,7 +264,7 @@ static int64_t bitfury_scanhash(struct thr_info *thr, struct work *work,
 	usb_write(bitfury, buf, 45, &amount, C_BF1_REQWORK);
 	cgtime(&info->tv_start);
 	/* Get response acknowledging work */
-	usb_read(bitfury, buf, 7, &amount, C_BF1_GETWORK);
+	usb_read(bitfury, buf, BF1MSGSIZE, &amount, C_BF1_GETWORK);
 
 	/* Only happens on startup */
 	if (unlikely(!info->prevwork[BF1ARRAY_SIZE]))
@@ -257,7 +272,7 @@ static int64_t bitfury_scanhash(struct thr_info *thr, struct work *work,
 
 	/* Search for what work the nonce matches in order of likelihood. Last
 	 * entry is end of result marker. */
-	for (i = 0; i < info->tot - 7; i += 7) {
+	for (i = 0; i < info->tot - BF1MSGSIZE; i += BF1MSGSIZE) {
 		uint32_t nonce;
 		int j;