[PARISC] pdc_console: fix bizarre panic on boot

Commit 721fdf34167580ff98263c74cead8871d76936e6 introduced a subtle bug
by accidently removing the "static" from iodc_dbuf. This resulted in, what
appeared to be, a trap without *current set to a task. Probably the result of
a trap in real mode while calling firmware.

Also do other misc clean ups. Since the only input from firmware is non
blocking, share iodc_dbuf between input and output, and spinlock the
only callers.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c
index e7afc899d717..ccb68090781e 100644
--- a/arch/parisc/kernel/pdc_cons.c
+++ b/arch/parisc/kernel/pdc_cons.c
@@ -52,15 +52,30 @@
 #include <linux/tty.h>
 #include <asm/pdc.h>            /* for iodc_call() proto and friends */
 
+static spinlock_t pdc_console_lock = SPIN_LOCK_UNLOCKED;
 
 static void pdc_console_write(struct console *co, const char *s, unsigned count)
 {
-        pdc_iodc_print(s, count);
+        int i = 0;
+        unsigned long flags;
+
+        spin_lock_irqsave(&pdc_console_lock, flags);
+        do {
+                i += pdc_iodc_print(s + i, count - i);
+        } while (i < count);
+        spin_unlock_irqrestore(&pdc_console_lock, flags);
 }
 
 int pdc_console_poll_key(struct console *co)
 {
-        return pdc_iodc_getc();
+        int c;
+        unsigned long flags;
+
+        spin_lock_irqsave(&pdc_console_lock, flags);
+        c = pdc_iodc_getc();
+        spin_unlock_irqrestore(&pdc_console_lock, flags);
+
+        return c;
 }
 
 static int pdc_console_setup(struct console *co, char *options)