[PATCH] powerpc: reorg RTAS delay code

This patch attempts to handle RTAS "busy" return codes in a more simple
and consistent manner.  Typical callers of RTAS shouldn't have to
manage wait times and delay calls.

This patch also changes the kernel to use msleep() rather than udelay()
when a runtime delay is necessary.  This will avoid CPU soft lockups
for extended delay conditions.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 4 insertions, 21 deletions

diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index aaf384c3f04a..1442b63a75da 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c
@@ -365,20 +365,12 @@ static int rtas_excl_release(struct inode *inode, struct file *file)
 
 static void manage_flash(struct rtas_manage_flash_t *args_buf)
 {
-        unsigned int wait_time;
         s32 rc;
 
-        while (1) {
+        do {
                 rc = rtas_call(rtas_token("ibm,manage-flash-image"), 1, 
                                1, NULL, args_buf->op);
-                if (rc == RTAS_RC_BUSY)
-                        udelay(1);
-                else if (rtas_is_extended_busy(rc)) {
-                        wait_time = rtas_extended_busy_delay_time(rc);
-                        udelay(wait_time * 1000);
-                } else
-                        break;
-        }
+        } while (rtas_busy_delay(rc));
 
         args_buf->status = rc;
 }
@@ -451,27 +443,18 @@ static ssize_t manage_flash_write(struct file *file, const char __user *buf,
 static void validate_flash(struct rtas_validate_flash_t *args_buf)
 {
         int token = rtas_token("ibm,validate-flash-image");
-        unsigned int wait_time;
         int update_results;
         s32 rc; 
 
         rc = 0;
-        while(1) {
+        do {
                 spin_lock(&rtas_data_buf_lock);
                 memcpy(rtas_data_buf, args_buf->buf, VALIDATE_BUF_SIZE);
                 rc = rtas_call(token, 2, 2, &update_results, 
                                (u32) __pa(rtas_data_buf), args_buf->buf_size);
                 memcpy(args_buf->buf, rtas_data_buf, VALIDATE_BUF_SIZE);
                 spin_unlock(&rtas_data_buf_lock);
-                        
-                if (rc == RTAS_RC_BUSY)
-                        udelay(1);
-                else if (rtas_is_extended_busy(rc)) {
-                        wait_time = rtas_extended_busy_delay_time(rc);
-                        udelay(wait_time * 1000);
-                } else
-                        break;
-        }
+        } while (rtas_busy_delay(rc));
 
         args_buf->status = rc;
         args_buf->update_results = update_results;