p54spi: get rid of busy-wait loops

p54spi_wakeup and p54spi_tx_frame used busy-waiting loop
to poll for 'ready' bits in SPI_ADRS_HOST_INTERRUPTS register.
With this change in place 'WR_READY timeout' messages do not
show anymore.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 14 insertions, 27 deletions

diff --git a/drivers/net/wireless/p54/p54spi.c b/drivers/net/wireless/p54/p54spi.c
index 52023127cf37..59a5e778bb08 100644
--- a/drivers/net/wireless/p54/p54spi.c
+++ b/drivers/net/wireless/p54/p54spi.c
@@ -167,14 +167,13 @@ static const struct p54spi_spi_reg p54spi_registers_array[] =
 static int p54spi_wait_bit(struct p54s_priv *priv, u16 reg, __le32 bits)
 {
         int i;
-        __le32 buffer;
 
         for (i = 0; i < 2000; i++) {
-                p54spi_spi_read(priv, reg, &buffer, sizeof(buffer));
+                __le32 buffer = p54spi_read32(priv, reg);
                 if ((buffer & bits) == bits)
                         return 1;
 
-                msleep(1);
+                msleep(0);
         }
         return 0;
 }
@@ -185,10 +184,10 @@ static int p54spi_spi_write_dma(struct p54s_priv *priv, __le32 base,
         p54spi_write16(priv, SPI_ADRS_DMA_WRITE_CTRL,
                        cpu_to_le16(SPI_DMA_WRITE_CTRL_ENABLE));
 
-        if (p54spi_wait_bit(priv, SPI_ADRS_DMA_WRITE_CTRL,
-                            cpu_to_le32(HOST_ALLOWED)) == 0) {
+        if (!p54spi_wait_bit(priv, SPI_ADRS_DMA_WRITE_CTRL,
+                             cpu_to_le32(HOST_ALLOWED))) {
                 dev_err(&priv->spi->dev, "spi_write_dma not allowed "
-                        "to DMA write.");
+                        "to DMA write.\n");
                 return -EAGAIN;
         }
 
@@ -330,21 +329,15 @@ static inline void p54spi_int_ack(struct p54s_priv *priv, u32 val)
 
 static void p54spi_wakeup(struct p54s_priv *priv)
 {
-        unsigned long timeout;
-        u32 ints;
-
         /* wake the chip */
         p54spi_write32(priv, SPI_ADRS_ARM_INTERRUPTS,
                        cpu_to_le32(SPI_TARGET_INT_WAKEUP));
 
         /* And wait for the READY interrupt */
-        timeout = jiffies + HZ;
-
-        ints =  p54spi_read32(priv, SPI_ADRS_HOST_INTERRUPTS);
-        while (!(ints & SPI_HOST_INT_READY)) {
-                if (time_after(jiffies, timeout))
-                                goto out;
-                ints = p54spi_read32(priv, SPI_ADRS_HOST_INTERRUPTS);
+        if (!p54spi_wait_bit(priv, SPI_ADRS_HOST_INTERRUPTS,
+                             cpu_to_le32(SPI_HOST_INT_READY))) {
+                dev_err(&priv->spi->dev, "INT_READY timeout\n");
+                goto out;
         }
 
         p54spi_int_ack(priv, SPI_HOST_INT_READY);
@@ -432,9 +425,7 @@ static irqreturn_t p54spi_interrupt(int irq, void *config)
 static int p54spi_tx_frame(struct p54s_priv *priv, struct sk_buff *skb)
 {
         struct p54_hdr *hdr = (struct p54_hdr *) skb->data;
-        unsigned long timeout;
         int ret = 0;
-        u32 ints;
 
         p54spi_wakeup(priv);
 
@@ -442,15 +433,11 @@ static int p54spi_tx_frame(struct p54s_priv *priv, struct sk_buff *skb)
         if (ret < 0)
                 goto out;
 
-        timeout = jiffies + 2 * HZ;
-        ints = p54spi_read32(priv, SPI_ADRS_HOST_INTERRUPTS);
-        while (!(ints & SPI_HOST_INT_WR_READY)) {
-                if (time_after(jiffies, timeout)) {
-                        dev_err(&priv->spi->dev, "WR_READY timeout\n");
-                        ret = -1;
-                        goto out;
-                }
-                ints = p54spi_read32(priv, SPI_ADRS_HOST_INTERRUPTS);
+        if (!p54spi_wait_bit(priv, SPI_ADRS_HOST_INTERRUPTS,
+                             cpu_to_le32(SPI_HOST_INT_WR_READY))) {
+                dev_err(&priv->spi->dev, "WR_READY timeout\n");
+                ret = -1;
+                goto out;
         }
 
         p54spi_int_ack(priv, SPI_HOST_INT_WR_READY);