[S390] sclp: don't call local_bh_disable/_local_bh_enable if in_interrupt()

local_bh_disable/_local_bh_enable must not be called if in_irq() is
true. Besides that if in_interrupt() is true bottom halves are
disabled anyway.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 3457a9a31571..027cdc18df31 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -402,6 +402,7 @@ sclp_sync_wait(void)
         unsigned long flags;
         unsigned long cr0, cr0_sync;
         u64 timeout;
+        int irq_context;
 
         /* We'll be disabling timer interrupts, so we need a custom timeout
          * mechanism */
@@ -414,7 +415,9 @@ sclp_sync_wait(void)
         }
         local_irq_save(flags);
         /* Prevent bottom half from executing once we force interrupts open */
-        local_bh_disable();
+        irq_context = in_interrupt();
+        if (!irq_context)
+                local_bh_disable();
         /* Enable service-signal interruption, disable timer interrupts */
         trace_hardirqs_on();
         __ctl_store(cr0, 0, 0);
@@ -435,7 +438,8 @@ sclp_sync_wait(void)
         }
         local_irq_disable();
         __ctl_load(cr0, 0, 0);
-        _local_bh_enable();
+        if (!irq_context)
+                _local_bh_enable();
         local_irq_restore(flags);
 }