thodg/cgminer

diff --git a/cgminer.c b/cgminer.c
index 2370b6a..39b9d99 100644
--- a/cgminer.c
+++ b/cgminer.c
@@ -209,6 +209,7 @@ char *opt_klondike_options = NULL;
 #endif
 #ifdef USE_DRILLBIT
 char *opt_drillbit_options = NULL;
+bool opt_drillbit_autotune = false;
 #endif
 char *opt_bab_options = NULL;
 #ifdef USE_BITMINE_A1
@@ -1342,6 +1343,9 @@ static struct opt_table opt_config_table[] = {
         OPT_WITH_ARG("--drillbit-options",
                      set_drillbit_options, NULL, NULL,
                      "Set drillbit options <int|ext>:clock[:clock_divider][:voltage]"),
+        OPT_WITHOUT_ARG("--drillbit-autotune",
+                        opt_set_bool, &opt_drillbit_autotune,
+                        "Enable drillbit automatic clock speed tuning"),
 #endif
 	OPT_WITH_ARG("--expiry|-E",
 		     set_int_0_to_9999, opt_show_intval, &opt_expiry,
diff --git a/driver-drillbit.c b/driver-drillbit.c
index 856e331..3c61bb1 100644
--- a/driver-drillbit.c
+++ b/driver-drillbit.c
@@ -61,6 +61,15 @@ typedef struct {
 	uint8_t use_ext_clock; // Flag. Ignored on boards without external clocks
 } BoardConfig;
 
+typedef struct
+{
+	uint16_t chip_id;
+	uint8_t increase_clock;
+} AutoTuneRequest;
+
+#define SZ_SERIALISED_AUTOTUNEREQUEST 3
+static void serialise_autotune_request(char *buf, AutoTuneRequest *aq);
+
 #define CONFIG_PW1 (1<<0)
 #define CONFIG_PW2 (1<<1)
 
@@ -638,6 +647,44 @@ static bool drillbit_checkresults(struct thr_info *thr, struct work *work, uint3
 	return false;
 }
 
+/* Check if this ASIC should be tweaked up or down in clock speed */
+static void drillbit_check_autotune(struct thr_info *thr, struct drillbit_chip_info *chip)
+{
+	struct cgpu_info *drillbit = thr->cgpu;
+	AutoTuneRequest request;
+	char buf[SZ_SERIALISED_AUTOTUNEREQUEST+1];
+	int amount;
+	float ratio;
+
+	/* autotune tries to keep ratio of HW errors within these margins:
+	   every RETUNE_EVERY results (errors and successes totalled, error count should be between
+	   the low and high limits given.
+	*/
+	const int TUNE_UP_EVERY = 100;
+	const int ERROR_LOW = 1;
+	const int ERROR_HIGH = 3;
+
+	/* Check auto parameters */
+	if(chip->success_auto + chip->error_auto < TUNE_UP_EVERY && chip->error_auto < ERROR_HIGH*2)
+		return;
+
+	ratio = 100 * (float)chip->error_auto / (chip->success_auto + chip->error_auto);
+	applog(LOG_DEBUG, "Chip id %d has error ratio %3.1f%%", chip->chip_id, ratio);
+
+	if(chip->error_auto < ERROR_LOW || chip->error_auto > ERROR_HIGH) {
+		/* Value should be tweaked */
+		buf[0] = 'A';
+		request.chip_id = chip->chip_id;
+		request.increase_clock = chip->error_auto < ERROR_LOW;
+		serialise_autotune_request(&buf[1], &request);
+		usb_write_timeout(drillbit, buf, sizeof(buf), &amount, TIMEOUT, C_BF_AUTOTUNE);
+		usb_read_simple_response(drillbit, 'A', C_BF_AUTOTUNE);
+	}
+
+	chip->success_auto = 0;
+	chip->error_auto = 0;
+}
+
 // Check and submit back any pending work results from firmware,
 // returns number of successful results found
 static int check_for_results(struct thr_info *thr)
@@ -713,20 +760,18 @@ static int check_for_results(struct thr_info *thr)
 			goto cleanup;
 		}
 
-		found = false;
 		for(i = 0; i < response->num_nonces; i++) {
 			if (unlikely(thr->work_restart))
 				goto cleanup;
+			found = false;
 			for(k = 0; k < WORK_HISTORY_LEN; k++) {
 				/* NB we deliberately check all results against all work because sometimes ASICs seem to give multiple "valid" nonces,
 				   and this seems to avoid some result that would otherwise be rejected by the pool.
-
-				   However we only count one success per result set to avoid artificially inflating the hashrate.
-				   A smarter thing to do here might be to look at the full set of nonces in the response and start from the "best" one first.
 				*/
 				if (chip->current_work[k] && drillbit_checkresults(thr, chip->current_work[k], response->nonce[i])) {
 					if (!found) {
 						chip->success_count++;
+						chip->success_auto++;
 						successful_results++;
 						found = true;
 					}
@@ -735,14 +780,18 @@ static int check_for_results(struct thr_info *thr)
 		}
 		drvlog(LOG_DEBUG, "%s nonce %08x", (found ? "Good":"Bad"), response->num_nonces ? response->nonce[0] : 0);
 		if(!found && chip->state != IDLE && response->num_nonces > 0) {
-		  /* all nonces we got back from this chip were invalid */
-		  inc_hw_errors(thr);
-		  chip->error_count++;
+			/* all nonces we got back from this chip were invalid */
+			inc_hw_errors(thr);
+			chip->error_count++;
+			chip->error_auto++;
 		}
 		if(chip->state == WORKING_QUEUED && !response->is_idle)
 			chip->state = WORKING_NOQUEUED; // Time to queue up another piece of "next work"
 		else
 			chip->state = IDLE; // Uh-oh, we're totally out of work for this ASIC!
+
+		if(opt_drillbit_autotune && info->protocol_version >= 4)
+			drillbit_check_autotune(thr, chip);
 	}
 
 cleanup:
@@ -827,6 +876,7 @@ static int64_t drillbit_scanwork(struct thr_info *thr)
 				   some pools can create unusual delays early on */
 				drvlog(LOG_ERR, "Timing out unresponsive ASIC %d", info->chips[i].chip_id);
 				info->chips[i].timeout_count++;
+				info->chips[i].error_auto++;
 			}
 			info->chips[i].state = IDLE;
 			drillbit_send_work_to_chip(thr, &info->chips[i]);
@@ -986,6 +1036,12 @@ static void serialise_board_configV4(char *buf, BoardConfig *bc)
 	SERIALISE(bc->use_ext_clock);
 }
 
+static void serialise_autotune_request(char *buf, AutoTuneRequest *aq)
+{
+	size_t offset = 0;
+	SERIALISE(aq->chip_id);
+	SERIALISE(aq->increase_clock);
+}
 
 static void deserialise_identity(Identity *id, const char *buf)
 {
diff --git a/driver-drillbit.h b/driver-drillbit.h
index 20a75c0..373a3c7 100644
--- a/driver-drillbit.h
+++ b/driver-drillbit.h
@@ -47,6 +47,8 @@ struct drillbit_chip_info {
   uint32_t error_count;
   uint32_t timeout_count;
   uint32_t work_sent_count;
+  uint32_t success_auto;
+  uint32_t error_auto;
 };
 
 #endif /* BITFURY_H */
diff --git a/miner.h b/miner.h
index f557b0d..40d88ea 100644
--- a/miner.h
+++ b/miner.h
@@ -982,6 +982,7 @@ extern char *opt_klondike_options;
 #endif
 #ifdef USE_DRILLBIT
 extern char *opt_drillbit_options;
+extern bool opt_drillbit_autotune;
 #endif
 #ifdef USE_BAB
 extern char *opt_bab_options;
diff --git a/usbutils.h b/usbutils.h
index 5d918fd..b05882e 100644
--- a/usbutils.h
+++ b/usbutils.h
@@ -353,7 +353,8 @@ struct cg_usb_info {
 	USB_ADD_COMMAND(C_BF_IDENTIFY, "BFIdentify") \
 	USB_ADD_COMMAND(C_BF_DETECTCHIPS, "BFDetectChips") \
 	USB_ADD_COMMAND(C_BF_CONFIG, "BFConfig") \
-        USB_ADD_COMMAND(C_BF_GETTEMP, "BFGetTemp") \
+	USB_ADD_COMMAND(C_BF_GETTEMP, "BFGetTemp") \
+	USB_ADD_COMMAND(C_BF_AUTOTUNE, "BFAutoTune") \
 	USB_ADD_COMMAND(C_ATMEL_RESET, "AtmelReset") \
 	USB_ADD_COMMAND(C_ATMEL_OPEN, "AtmelOpen") \
 	USB_ADD_COMMAND(C_ATMEL_INIT, "AtmelInit") \