Merge branch 'for-2.6.26' of master.kernel.org:/pub/scm/linux/kernel/git/jwboyer/powerpc-4xx into merge

3 files changed, 28 insertions, 14 deletions

diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index 02c8e305b14f..e81d59d78910 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -497,7 +497,7 @@ static int atmel_spi_setup(struct spi_device *spi)
         struct atmel_spi        *as;
         u32                     scbr, csr;
         unsigned int            bits = spi->bits_per_word;
-        unsigned long           bus_hz, sck_hz;
+        unsigned long           bus_hz;
         unsigned int            npcs_pin;
         int                     ret;
 
@@ -536,14 +536,25 @@ static int atmel_spi_setup(struct spi_device *spi)
                 return -EINVAL;
         }
 
-        /* speed zero convention is used by some upper layers */
+        /*
+         * Pre-new_1 chips start out at half the peripheral
+         * bus speed.
+         */
         bus_hz = clk_get_rate(as->clk);
+        if (!as->new_1)
+                bus_hz /= 2;
+
         if (spi->max_speed_hz) {
-                /* assume div32/fdiv/mbz == 0 */
-                if (!as->new_1)
-                        bus_hz /= 2;
-                scbr = ((bus_hz + spi->max_speed_hz - 1)
-                        / spi->max_speed_hz);
+                /*
+                 * Calculate the lowest divider that satisfies the
+                 * constraint, assuming div32/fdiv/mbz == 0.
+                 */
+                scbr = DIV_ROUND_UP(bus_hz, spi->max_speed_hz);
+
+                /*
+                 * If the resulting divider doesn't fit into the
+                 * register bitfield, we can't satisfy the constraint.
+                 */
                 if (scbr >= (1 << SPI_SCBR_SIZE)) {
                         dev_dbg(&spi->dev,
                                 "setup: %d Hz too slow, scbr %u; min %ld Hz\n",
@@ -551,8 +562,8 @@ static int atmel_spi_setup(struct spi_device *spi)
                         return -EINVAL;
                 }
         } else
+                /* speed zero means "as slow as possible" */
                 scbr = 0xff;
-        sck_hz = bus_hz / scbr;
 
         csr = SPI_BF(SCBR, scbr) | SPI_BF(BITS, bits - 8);
         if (spi->mode & SPI_CPOL)
@@ -589,7 +600,7 @@ static int atmel_spi_setup(struct spi_device *spi)
 
         dev_dbg(&spi->dev,
                 "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
-                sck_hz, bits, spi->mode, spi->chip_select, csr);
+                bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
 
         spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
 
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index a9ac1fdb3094..7fea3cf4588a 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -608,6 +608,7 @@ static void pump_transfers(unsigned long data)
         u8 width;
         u16 cr, dma_width, dma_config;
         u32 tranf_success = 1;
+        u8 full_duplex = 0;
 
         /* Get current state information */
         message = drv_data->cur_msg;
@@ -658,6 +659,7 @@ static void pump_transfers(unsigned long data)
         }
 
         if (transfer->rx_buf != NULL) {
+                full_duplex = transfer->tx_buf != NULL;
                 drv_data->rx = transfer->rx_buf;
                 drv_data->rx_end = drv_data->rx + transfer->len;
                 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
@@ -740,7 +742,8 @@ static void pump_transfers(unsigned long data)
          * successful use different way to r/w according to
          * drv_data->cur_chip->enable_dma
          */
-        if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
+        if (!full_duplex && drv_data->cur_chip->enable_dma
+                                && drv_data->len > 6) {
 
                 disable_dma(drv_data->dma_channel);
                 clear_dma_irqstat(drv_data->dma_channel);
@@ -828,7 +831,7 @@ static void pump_transfers(unsigned long data)
                 /* IO mode write then read */
                 dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
 
-                if (drv_data->tx != NULL && drv_data->rx != NULL) {
+                if (full_duplex) {
                         /* full duplex mode */
                         BUG_ON((drv_data->tx_end - drv_data->tx) !=
                                (drv_data->rx_end - drv_data->rx));
diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c
index 34bfb7dd7764..0885cc357a37 100644
--- a/drivers/spi/spi_s3c24xx.c
+++ b/drivers/spi/spi_s3c24xx.c
@@ -125,10 +125,10 @@ static int s3c24xx_spi_setupxfer(struct spi_device *spi,
         /* is clk = pclk / (2 * (pre+1)), or is it
          *    clk = (pclk * 2) / ( pre + 1) */
 
-        div = (div / 2) - 1;
+        div /= 2;
 
-        if (div < 0)
-                div = 1;
+        if (div > 0)
+                div -= 1;
 
         if (div > 255)
                 div = 255;