[PATCH] ipmi: various si cleanup

A number of small changes for the various system interface drivers,
consolidated from a number of patches from Matt Domsch.

Clear B2H_ATN and drain the BMC message buffer on command timeout.  This
prevents further commands from failing after a timeout.

Add bt_debug and smic_debug module parameters, expose them in sysfs.  This
lets you enable and disable debugging messages at runtime.

Unsigned jiffies math in ipmi_si_intf.c causes a too-large value to be passed
to ->event() after jiffies wrap-around.  The BT driver had caught this, but
didn't know how to fix it.  Now all calls to ->event() use a sane value for
time.

Increase timeout for commands handed to the BT driver from 2 seconds to 5
seconds.  This is necessary particularly when the previous command was a
"Clear SEL", as that command completes, yet the BMC isn't really ready to
handle another command yet.

Silence BT debugging messages which were being printed on the console.

Increase SMIC timeout form 1/10s to 2s.  This is needed on Dell PowerEdge 2650
and PowerEdge 750 with ERA/O cards to allow commands to complete without
timing out.

Adds kcs_debug module param, to match behavior of BT and SMIC.  This also
prevents messages from being sent to the console unless explicitly requested.

Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/char/ipmi/ipmi_bt_sm.c

@@ -28,6 +28,8 @@
 
 #include <linux/kernel.h> /* For printk. */
 #include <linux/string.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/ipmi_msgdefs.h>		/* for completion codes */
 #include "ipmi_si_sm.h"
 
@@ -36,6 +38,8 @@ static int bt_debug = 0x00;	/* Production value 0, see following flags */
 #define	BT_DEBUG_ENABLE	1
 #define BT_DEBUG_MSG	2
 #define BT_DEBUG_STATES	4
+module_param(bt_debug, int, 0644);
+MODULE_PARM_DESC(bt_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
 
 /* Typical "Get BT Capabilities" values are 2-3 retries, 5-10 seconds,
    and 64 byte buffers.  However, one HP implementation wants 255 bytes of
@@ -43,7 +47,7 @@ static int bt_debug = 0x00;	/* Production value 0, see following flags */
    Since the Open IPMI architecture is single-message oriented at this
    stage, the queue depth of BT is of no concern. */
 
-#define BT_NORMAL_TIMEOUT	2000000	/* seconds in microseconds */
+#define BT_NORMAL_TIMEOUT	5000000	/* seconds in microseconds */
 #define BT_RETRY_LIMIT		2
 #define BT_RESET_DELAY		6000000	/* 6 seconds after warm reset */
 
@@ -202,7 +206,7 @@ static int bt_get_result(struct si_sm_data *bt,
 	msg_len = bt->read_count - 2;		/* account for length & seq */
 	/* Always NetFn, Cmd, cCode */
 	if (msg_len < 3 || msg_len > IPMI_MAX_MSG_LENGTH) {
-		printk(KERN_WARNING "BT results: bad msg_len = %d\n", msg_len);
+		printk(KERN_DEBUG "BT results: bad msg_len = %d\n", msg_len);
 		data[0] = bt->write_data[1] | 0x4;	/* Kludge a response */
 		data[1] = bt->write_data[3];
 		data[2] = IPMI_ERR_UNSPECIFIED;
@@ -240,7 +244,7 @@ static void reset_flags(struct si_sm_data *bt)
 	       BT_CONTROL(BT_B_BUSY);
 	BT_CONTROL(BT_CLR_WR_PTR);
 	BT_CONTROL(BT_SMS_ATN);
-#ifdef DEVELOPMENT_ONLY_NOT_FOR_PRODUCTION
+
 	if (BT_STATUS & BT_B2H_ATN) {
 		int i;
 		BT_CONTROL(BT_H_BUSY);
@@ -250,7 +254,6 @@ static void reset_flags(struct si_sm_data *bt)
 		       BMC2HOST;
 		BT_CONTROL(BT_H_BUSY);
 	}
-#endif
 }
 
 static inline void write_all_bytes(struct si_sm_data *bt)
@@ -295,7 +298,7 @@ static inline int read_all_bytes(struct si_sm_data *bt)
 	    	printk ("\n");
 	}
 	if (bt->seq != bt->write_data[2])	/* idiot check */
-		printk(KERN_WARNING "BT: internal error: sequence mismatch\n");
+		printk(KERN_DEBUG "BT: internal error: sequence mismatch\n");
 
 	/* per the spec, the (NetFn, Seq, Cmd) tuples should match */
 	if ((bt->read_data[3] == bt->write_data[3]) &&		/* Cmd */
@@ -321,18 +324,18 @@ static void error_recovery(struct si_sm_data *bt, char *reason)
 	bt->timeout = BT_NORMAL_TIMEOUT; /* various places want to retry */
 
 	status = BT_STATUS;
-	printk(KERN_WARNING "BT: %s in %s %s ", reason, STATE2TXT,
+	printk(KERN_DEBUG "BT: %s in %s %s\n", reason, STATE2TXT,
 	       STATUS2TXT(buf));
 
 	(bt->error_retries)++;
 	if (bt->error_retries > BT_RETRY_LIMIT) {
-		printk("retry limit (%d) exceeded\n", BT_RETRY_LIMIT);
+		printk(KERN_DEBUG "retry limit (%d) exceeded\n", BT_RETRY_LIMIT);
 		bt->state = BT_STATE_HOSED;
 		if (!bt->nonzero_status)
 			printk(KERN_ERR "IPMI: BT stuck, try power cycle\n");
 		else if (bt->seq == FIRST_SEQ + BT_RETRY_LIMIT) {
 			/* most likely during insmod */
-			printk(KERN_WARNING "IPMI: BT reset (takes 5 secs)\n");
+			printk(KERN_DEBUG "IPMI: BT reset (takes 5 secs)\n");
         		bt->state = BT_STATE_RESET1;
 		}
 	return;
@@ -340,11 +343,11 @@ static void error_recovery(struct si_sm_data *bt, char *reason)
 
 	/* Sometimes the BMC queues get in an "off-by-one" state...*/
 	if ((bt->state == BT_STATE_B2H_WAIT) && (status & BT_B2H_ATN)) {
-    		printk("retry B2H_WAIT\n");
+    		printk(KERN_DEBUG "retry B2H_WAIT\n");
 		return;
 	}
 
-	printk("restart command\n");
+	printk(KERN_DEBUG "restart command\n");
 	bt->state = BT_STATE_RESTART;
 }
 
@@ -372,17 +375,6 @@ static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
 	       return SI_SM_HOSED;
 
 	if (bt->state != BT_STATE_IDLE) {	/* do timeout test */
-
-		/* Certain states, on error conditions, can lock up a CPU
-		   because they are effectively in an infinite loop with
-		   CALL_WITHOUT_DELAY (right back here with time == 0).
-		   Prevent infinite lockup by ALWAYS decrementing timeout. */
-
-    	/* FIXME: bt_event is sometimes called with time > BT_NORMAL_TIMEOUT
-              (noticed in ipmi_smic_sm.c January 2004) */
-
-		if ((time <= 0) || (time >= BT_NORMAL_TIMEOUT))
-		       time = 100;
 		bt->timeout -= time;
 		if ((bt->timeout < 0) && (bt->state < BT_STATE_RESET1)) {
 			error_recovery(bt, "timed out");

drivers/char/ipmi/ipmi_kcs_sm.c

@@ -38,16 +38,24 @@
  */
 
 #include <linux/kernel.h> /* For printk. */
+#include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/string.h>
 #include <linux/ipmi_msgdefs.h>		/* for completion codes */
 #include "ipmi_si_sm.h"
 
-/* Set this if you want a printout of why the state machine was hosed
-   when it gets hosed. */
-#define DEBUG_HOSED_REASON
+/* kcs_debug is a bit-field
+ *	KCS_DEBUG_ENABLE -	turned on for now
+ *	KCS_DEBUG_MSG    -	commands and their responses
+ *	KCS_DEBUG_STATES -	state machine
+ */
+#define KCS_DEBUG_STATES	4
+#define KCS_DEBUG_MSG		2
+#define	KCS_DEBUG_ENABLE	1
 
-/* Print the state machine state on entry every time. */
-#undef DEBUG_STATE
+static int kcs_debug;
+module_param(kcs_debug, int, 0644);
+MODULE_PARM_DESC(kcs_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
 
 /* The states the KCS driver may be in. */
 enum kcs_states {
@@ -175,9 +183,8 @@ static inline void start_error_recovery(struct si_sm_data *kcs, char *reason)
 {
 	(kcs->error_retries)++;
 	if (kcs->error_retries > MAX_ERROR_RETRIES) {
-#ifdef DEBUG_HOSED_REASON
-		printk("ipmi_kcs_sm: kcs hosed: %s\n", reason);
-#endif
+		if (kcs_debug & KCS_DEBUG_ENABLE)
+			printk(KERN_DEBUG "ipmi_kcs_sm: kcs hosed: %s\n", reason);
 		kcs->state = KCS_HOSED;
 	} else {
 		kcs->state = KCS_ERROR0;
@@ -248,14 +255,21 @@ static void restart_kcs_transaction(struct si_sm_data *kcs)
 static int start_kcs_transaction(struct si_sm_data *kcs, unsigned char *data,
 				 unsigned int size)
 {
+	unsigned int i;
+
 	if ((size < 2) || (size > MAX_KCS_WRITE_SIZE)) {
 		return -1;
 	}
-
 	if ((kcs->state != KCS_IDLE) && (kcs->state != KCS_HOSED)) {
 		return -2;
 	}
-
+	if (kcs_debug & KCS_DEBUG_MSG) {
+		printk(KERN_DEBUG "start_kcs_transaction -");
+		for (i = 0; i < size; i ++) {
+			printk(" %02x", (unsigned char) (data [i]));
+		}
+		printk ("\n");
+	}
 	kcs->error_retries = 0;
 	memcpy(kcs->write_data, data, size);
 	kcs->write_count = size;
@@ -305,9 +319,9 @@ static enum si_sm_result kcs_event(struct si_sm_data *kcs, long time)
 
 	status = read_status(kcs);
 
-#ifdef DEBUG_STATE
-	printk("  State = %d, %x\n", kcs->state, status);
-#endif
+	if (kcs_debug & KCS_DEBUG_STATES)
+		printk(KERN_DEBUG "KCS: State = %d, %x\n", kcs->state, status);
+
 	/* All states wait for ibf, so just do it here. */
 	if (!check_ibf(kcs, status, time))
 		return SI_SM_CALL_WITH_DELAY;

drivers/char/ipmi/ipmi_si_intf.c

@@ -819,7 +819,7 @@ static void smi_timeout(unsigned long data)
 	enum si_sm_result smi_result;
 	unsigned long     flags;
 	unsigned long     jiffies_now;
-	unsigned long     time_diff;
+	long              time_diff;
 #ifdef DEBUG_TIMING
 	struct timeval    t;
 #endif
@@ -835,7 +835,7 @@ static void smi_timeout(unsigned long data)
 	printk("**Timer: %d.%9.9d\n", t.tv_sec, t.tv_usec);
 #endif
 	jiffies_now = jiffies;
-	time_diff = ((jiffies_now - smi_info->last_timeout_jiffies)
+	time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies)
 		     * SI_USEC_PER_JIFFY);
 	smi_result = smi_event_handler(smi_info, time_diff);
 

drivers/char/ipmi/ipmi_smic_sm.c

@@ -43,6 +43,8 @@
 
 #include <linux/kernel.h> /* For printk. */
 #include <linux/string.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/ipmi_msgdefs.h>		/* for completion codes */
 #include "ipmi_si_sm.h"
 
@@ -56,6 +58,8 @@
 #define	SMIC_DEBUG_ENABLE	1
 
 static int smic_debug = 1;
+module_param(smic_debug, int, 0644);
+MODULE_PARM_DESC(smic_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
 
 enum smic_states {
 	SMIC_IDLE,
@@ -76,7 +80,7 @@ enum smic_states {
 #define SMIC_MAX_ERROR_RETRIES 3
 
 /* Timeouts in microseconds. */
-#define SMIC_RETRY_TIMEOUT 100000
+#define SMIC_RETRY_TIMEOUT 2000000
 
 /* SMIC Flags Register Bits */
 #define SMIC_RX_DATA_READY	0x80