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>

diff --git a/drivers/net/wireless/p54/p54spi.c b/drivers/net/wireless/p54/p54spi.c
index 5202312..59a5e77 100644 (file)
--- 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);