spi_bitbang: always grab lock with irqs blocked

Fix a glitch reported by lockdep in the spi_bitbang code: it needs to
consistently block IRQs when holding that spinlock.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
index 81639c6be1c7..f7f8580edad8 100644
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -184,6 +184,7 @@ int spi_bitbang_setup(struct spi_device *spi)
         struct spi_bitbang_cs   *cs = spi->controller_state;
         struct spi_bitbang      *bitbang;
         int                     retval;
+        unsigned long           flags;
 
         bitbang = spi_master_get_devdata(spi->master);
 
@@ -222,12 +223,12 @@ int spi_bitbang_setup(struct spi_device *spi)
          */
 
         /* deselect chip (low or high) */
-        spin_lock(&bitbang->lock);
+        spin_lock_irqsave(&bitbang->lock, flags);
         if (!bitbang->busy) {
                 bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
                 ndelay(cs->nsecs);
         }
-        spin_unlock(&bitbang->lock);
+        spin_unlock_irqrestore(&bitbang->lock, flags);
 
         return 0;
 }