openwrt/target/linux/generic-2.6/patches/009-revert_intel_flash_breakage.patch

--- linux.old/drivers/mtd/chips/cfi_cmdset_0001.c	2007-02-13 02:41:50.816650352 +0100
+++ linux.dev/drivers/mtd/chips/cfi_cmdset_0001.c	2007-02-13 02:42:13.782159064 +0100
@@ -908,7 +908,7 @@
 
 static int __xipram xip_wait_for_operation(
 		struct map_info *map, struct flchip *chip,
-		unsigned long adr, unsigned int chip_op_time )
+		unsigned long adr, int *chip_op_time )
 {
 	struct cfi_private *cfi = map->fldrv_priv;
 	struct cfi_pri_intelext *cfip = cfi->cmdset_priv;
@@ -917,7 +917,7 @@
 	flstate_t oldstate, newstate;
 
        	start = xip_currtime();
-	usec = chip_op_time * 8;
+	usec = *chip_op_time * 8;
 	if (usec == 0)
 		usec = 500000;
 	done = 0;
@@ -1027,8 +1027,8 @@
 #define XIP_INVAL_CACHED_RANGE(map, from, size)  \
 	INVALIDATE_CACHED_RANGE(map, from, size)
 
-#define INVAL_CACHE_AND_WAIT(map, chip, cmd_adr, inval_adr, inval_len, usec) \
-	xip_wait_for_operation(map, chip, cmd_adr, usec)
+#define INVAL_CACHE_AND_WAIT(map, chip, cmd_adr, inval_adr, inval_len, p_usec) \
+	xip_wait_for_operation(map, chip, cmd_adr, p_usec)
 
 #else
 
@@ -1040,65 +1040,65 @@
 static int inval_cache_and_wait_for_operation(
 		struct map_info *map, struct flchip *chip,
 		unsigned long cmd_adr, unsigned long inval_adr, int inval_len,
-		unsigned int chip_op_time)
+		int *chip_op_time )
 {
 	struct cfi_private *cfi = map->fldrv_priv;
 	map_word status, status_OK = CMD(0x80);
-	int chip_state = chip->state;
-	unsigned int timeo, sleep_time;
+	int z, chip_state = chip->state;
+	unsigned long timeo;
 
 	spin_unlock(chip->mutex);
 	if (inval_len)
 		INVALIDATE_CACHED_RANGE(map, inval_adr, inval_len);
+	if (*chip_op_time)
+		cfi_udelay(*chip_op_time);
 	spin_lock(chip->mutex);
 
-	/* set our timeout to 8 times the expected delay */
-	timeo = chip_op_time * 8;
-	if (!timeo)
-		timeo = 500000;
-	sleep_time = chip_op_time / 2;
+	timeo = *chip_op_time * 8 * HZ / 1000000;
+	if (timeo < HZ/2)
+		timeo = HZ/2;
+	timeo += jiffies;
 
+	z = 0;
 	for (;;) {
+		if (chip->state != chip_state) {
+			/* Someone's suspended the operation: sleep */
+			DECLARE_WAITQUEUE(wait, current);
+
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			add_wait_queue(&chip->wq, &wait);
+			spin_unlock(chip->mutex);
+			schedule();
+			remove_wait_queue(&chip->wq, &wait);
+			timeo = jiffies + (HZ / 2); /* FIXME */
+			spin_lock(chip->mutex);
+			continue;
+		}
+
 		status = map_read(map, cmd_adr);
 		if (map_word_andequal(map, status, status_OK, status_OK))
 			break;
 
-		if (!timeo) {
+		/* OK Still waiting */
+		if (time_after(jiffies, timeo)) {
 			map_write(map, CMD(0x70), cmd_adr);
 			chip->state = FL_STATUS;
 			return -ETIME;
 		}
 
-		/* OK Still waiting. Drop the lock, wait a while and retry. */
+		/* Latency issues. Drop the lock, wait a while and retry */
+		z++;
 		spin_unlock(chip->mutex);
-		if (sleep_time >= 1000000/HZ) {
-			/*
-			 * Half of the normal delay still remaining
-			 * can be performed with a sleeping delay instead
-			 * of busy waiting.
-			 */
-			msleep(sleep_time/1000);
-			timeo -= sleep_time;
-			sleep_time = 1000000/HZ;
-		} else {
-			udelay(1);
-			cond_resched();
-			timeo--;
-		}
+		cfi_udelay(1);
 		spin_lock(chip->mutex);
-
-		while (chip->state != chip_state) {
-			/* Someone's suspended the operation: sleep */
-			DECLARE_WAITQUEUE(wait, current);
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			add_wait_queue(&chip->wq, &wait);
-			spin_unlock(chip->mutex);
-			schedule();
-			remove_wait_queue(&chip->wq, &wait);
-			spin_lock(chip->mutex);
-		}
 	}
 
+	if (!z) {
+		if (!--(*chip_op_time))
+			*chip_op_time = 1;
+	} else if (z > 1)
+		++(*chip_op_time);
+
 	/* Done and happy. */
  	chip->state = FL_STATUS;
 	return 0;
@@ -1107,7 +1107,8 @@
 #endif
 
 #define WAIT_TIMEOUT(map, chip, adr, udelay) \
-	INVAL_CACHE_AND_WAIT(map, chip, adr, 0, 0, udelay);
+	({ int __udelay = (udelay); \
+	   INVAL_CACHE_AND_WAIT(map, chip, adr, 0, 0, &__udelay); })
 
 
 static int do_point_onechip (struct map_info *map, struct flchip *chip, loff_t adr, size_t len)
@@ -1331,7 +1332,7 @@
 
 	ret = INVAL_CACHE_AND_WAIT(map, chip, adr,
 				   adr, map_bankwidth(map),
-				   chip->word_write_time);
+				   &chip->word_write_time);
 	if (ret) {
 		xip_enable(map, chip, adr);
 		printk(KERN_ERR "%s: word write error (status timeout)\n", map->name);
@@ -1568,7 +1569,7 @@
 
 	ret = INVAL_CACHE_AND_WAIT(map, chip, cmd_adr,
 				   adr, len,
-				   chip->buffer_write_time);
+				   &chip->buffer_write_time);
 	if (ret) {
 		map_write(map, CMD(0x70), cmd_adr);
 		chip->state = FL_STATUS;
@@ -1703,7 +1704,7 @@
 
 	ret = INVAL_CACHE_AND_WAIT(map, chip, adr,
 				   adr, len,
-				   chip->erase_time);
+				   &chip->erase_time);
 	if (ret) {
 		map_write(map, CMD(0x70), adr);
 		chip->state = FL_STATUS;