macintosh/adb: Rework printk output again

Avoid the KERN_CONT problem by avoiding message fragments. The problem
arises during async ADB bus probing, when ADB messages may get mixed up
with other messages. See also, commit 4bcc595ccd80 ("printk: reinstate
KERN_CONT for printing continuation lines").

Remove a number of printk() continuation lines by logging handler
changes in adb_try_handler_change() instead.

This patch addresses the problematic use of "\n" at the beginning of
pr_cont() messages, which got overlooked in commit f2be6295684b
("macintosh/adb: Properly mark continued kernel messages").

That commit also changed printk(KERN_DEBUG ...) to pr_debug(...), which
hinders work on low-level ADB driver bugs. Revert that change.

Cc: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
index 76e98f0f7a3e..e49d1f287a17 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c
@@ -203,15 +203,15 @@ static int adb_scan_bus(void)
         }
 
         /* Now fill in the handler_id field of the adb_handler entries. */
-        pr_debug("adb devices:\n");
         for (i = 1; i < 16; i++) {
                 if (adb_handler[i].original_address == 0)
                         continue;
                 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
                             (i << 4) | 0xf);
                 adb_handler[i].handler_id = req.reply[2];
-                pr_debug(" [%d]: %d %x\n", i, adb_handler[i].original_address,
-                         adb_handler[i].handler_id);
+                printk(KERN_DEBUG "adb device [%d]: %d 0x%X\n", i,
+                       adb_handler[i].original_address,
+                       adb_handler[i].handler_id);
                 devmask |= 1 << i;
         }
         return devmask;
@@ -579,6 +579,8 @@ adb_try_handler_change(int address, int new_id)
         mutex_lock(&adb_handler_mutex);
         ret = try_handler_change(address, new_id);
         mutex_unlock(&adb_handler_mutex);
+        if (ret)
+                pr_debug("adb handler change: [%d] 0x%X\n", address, new_id);
         return ret;
 }
 EXPORT_SYMBOL(adb_try_handler_change);