spi_mpc83xx: split mpc83xx_spi_work() into two routines

mpc83xx_spi_work() is quite large, with up to five indentation levels and
is quite difficult to read.

So, split the function in two parts:
1. mpc83xx_spi_work() now only traverse queued spi messages;
2. mpc83xx_spi_do_one_msg() only manages single messages.

There should be no functional changes.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 60 insertions, 55 deletions

diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 273940d3938d..e854ac0d413a 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -350,71 +350,76 @@ static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
         return mpc83xx_spi->count;
 }
 
-static void mpc83xx_spi_work(struct work_struct *work)
+static void mpc83xx_spi_do_one_msg(struct spi_message *m)
 {
-        struct mpc83xx_spi *mpc83xx_spi =
-                container_of(work, struct mpc83xx_spi, work);
-
-        spin_lock_irq(&mpc83xx_spi->lock);
-        mpc83xx_spi->busy = 1;
-        while (!list_empty(&mpc83xx_spi->queue)) {
-                struct spi_message *m;
-                struct spi_device *spi;
-                struct spi_transfer *t = NULL;
-                unsigned cs_change;
-                int status, nsecs = 50;
-
-                m = container_of(mpc83xx_spi->queue.next,
-                                struct spi_message, queue);
-                list_del_init(&m->queue);
-                spin_unlock_irq(&mpc83xx_spi->lock);
-
-                spi = m->spi;
-                cs_change = 1;
-                status = 0;
-                list_for_each_entry(t, &m->transfers, transfer_list) {
-                        if (t->bits_per_word || t->speed_hz) {
-                                /* Don't allow changes if CS is active */
-                                status = -EINVAL;
-
-                                if (cs_change)
-                                        status = mpc83xx_spi_setup_transfer(spi, t);
-                                if (status < 0)
-                                        break;
-                        }
-
-                        if (cs_change) {
-                                mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE);
-                                ndelay(nsecs);
-                        }
-                        cs_change = t->cs_change;
-                        if (t->len)
-                                status = mpc83xx_spi_bufs(spi, t);
-                        if (status) {
-                                status = -EMSGSIZE;
+        struct spi_device *spi = m->spi;
+        struct spi_transfer *t;
+        unsigned int cs_change;
+        const int nsecs = 50;
+        int status;
+
+        cs_change = 1;
+        status = 0;
+        list_for_each_entry(t, &m->transfers, transfer_list) {
+                if (t->bits_per_word || t->speed_hz) {
+                        /* Don't allow changes if CS is active */
+                        status = -EINVAL;
+
+                        if (cs_change)
+                                status = mpc83xx_spi_setup_transfer(spi, t);
+                        if (status < 0)
                                 break;
-                        }
-                        m->actual_length += t->len;
-
-                        if (t->delay_usecs)
-                                udelay(t->delay_usecs);
+                }
 
-                        if (cs_change) {
-                                ndelay(nsecs);
-                                mpc83xx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
-                                ndelay(nsecs);
-                        }
+                if (cs_change) {
+                        mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE);
+                        ndelay(nsecs);
+                }
+                cs_change = t->cs_change;
+                if (t->len)
+                        status = mpc83xx_spi_bufs(spi, t);
+                if (status) {
+                        status = -EMSGSIZE;
+                        break;
                 }
+                m->actual_length += t->len;
 
-                m->status = status;
-                m->complete(m->context);
+                if (t->delay_usecs)
+                        udelay(t->delay_usecs);
 
-                if (status || !cs_change) {
+                if (cs_change) {
                         ndelay(nsecs);
                         mpc83xx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
+                        ndelay(nsecs);
                 }
+        }
+
+        m->status = status;
+        m->complete(m->context);
+
+        if (status || !cs_change) {
+                ndelay(nsecs);
+                mpc83xx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
+        }
+
+        mpc83xx_spi_setup_transfer(spi, NULL);
+}
+
+static void mpc83xx_spi_work(struct work_struct *work)
+{
+        struct mpc83xx_spi *mpc83xx_spi = container_of(work, struct mpc83xx_spi,
+                                                       work);
+
+        spin_lock_irq(&mpc83xx_spi->lock);
+        mpc83xx_spi->busy = 1;
+        while (!list_empty(&mpc83xx_spi->queue)) {
+                struct spi_message *m = container_of(mpc83xx_spi->queue.next,
+                                                   struct spi_message, queue);
+
+                list_del_init(&m->queue);
+                spin_unlock_irq(&mpc83xx_spi->lock);
 
-                mpc83xx_spi_setup_transfer(spi, NULL);
+                mpc83xx_spi_do_one_msg(m);
 
                 spin_lock_irq(&mpc83xx_spi->lock);
         }