Blackfin SPI driver: use cpu_relax() to replace continue in while busywait

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 39 insertions, 39 deletions

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index a85bcb306590..0e33b5aa35fb 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -186,7 +186,7 @@ static int flush(struct driver_data *drv_data)
 
         /* wait for stop and clear stat */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && limit--)
-                continue;
+                cpu_relax();
 
         write_STAT(drv_data, BIT_STAT_CLR);
 
@@ -262,7 +262,7 @@ static void null_writer(struct driver_data *drv_data)
         while (drv_data->tx < drv_data->tx_end) {
                 write_TDBR(drv_data, 0);
                 while ((read_STAT(drv_data) & BIT_STAT_TXS))
-                        continue;
+                        cpu_relax();
                 drv_data->tx += n_bytes;
         }
 }
@@ -274,7 +274,7 @@ static void null_reader(struct driver_data *drv_data)
 
         while (drv_data->rx < drv_data->rx_end) {
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 dummy_read(drv_data);
                 drv_data->rx += n_bytes;
         }
@@ -287,12 +287,12 @@ static void u8_writer(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         while (drv_data->tx < drv_data->tx_end) {
                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
                 while (read_STAT(drv_data) & BIT_STAT_TXS)
-                        continue;
+                        cpu_relax();
                 ++drv_data->tx;
         }
 }
@@ -303,14 +303,14 @@ static void u8_cs_chg_writer(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         while (drv_data->tx < drv_data->tx_end) {
                 cs_active(drv_data, chip);
 
                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
                 while (read_STAT(drv_data) & BIT_STAT_TXS)
-                        continue;
+                        cpu_relax();
 
                 cs_deactive(drv_data, chip);
 
@@ -325,7 +325,7 @@ static void u8_reader(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         /* clear TDBR buffer before read(else it will be shifted out) */
         write_TDBR(drv_data, 0xFFFF);
@@ -334,13 +334,13 @@ static void u8_reader(struct driver_data *drv_data)
 
         while (drv_data->rx < drv_data->rx_end - 1) {
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
                 ++drv_data->rx;
         }
 
         while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                continue;
+                cpu_relax();
         *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
         ++drv_data->rx;
 }
@@ -351,7 +351,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         /* clear TDBR buffer before read(else it will be shifted out) */
         write_TDBR(drv_data, 0xFFFF);
@@ -363,7 +363,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
                 cs_deactive(drv_data, chip);
 
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 cs_active(drv_data, chip);
                 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
                 ++drv_data->rx;
@@ -371,7 +371,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
         cs_deactive(drv_data, chip);
 
         while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                continue;
+                cpu_relax();
         *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
         ++drv_data->rx;
 }
@@ -380,15 +380,15 @@ static void u8_duplex(struct driver_data *drv_data)
 {
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         /* in duplex mode, clk is triggered by writing of TDBR */
         while (drv_data->rx < drv_data->rx_end) {
                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
                 while (read_STAT(drv_data) & BIT_STAT_TXS)
-                        continue;
+                        cpu_relax();
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
                 ++drv_data->rx;
                 ++drv_data->tx;
@@ -401,16 +401,16 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         while (drv_data->rx < drv_data->rx_end) {
                 cs_active(drv_data, chip);
 
                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
                 while (read_STAT(drv_data) & BIT_STAT_TXS)
-                        continue;
+                        cpu_relax();
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
 
                 cs_deactive(drv_data, chip);
@@ -427,12 +427,12 @@ static void u16_writer(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         while (drv_data->tx < drv_data->tx_end) {
                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
                 while ((read_STAT(drv_data) & BIT_STAT_TXS))
-                        continue;
+                        cpu_relax();
                 drv_data->tx += 2;
         }
 }
@@ -443,14 +443,14 @@ static void u16_cs_chg_writer(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         while (drv_data->tx < drv_data->tx_end) {
                 cs_active(drv_data, chip);
 
                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
                 while ((read_STAT(drv_data) & BIT_STAT_TXS))
-                        continue;
+                        cpu_relax();
 
                 cs_deactive(drv_data, chip);
 
@@ -465,7 +465,7 @@ static void u16_reader(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         /* clear TDBR buffer before read(else it will be shifted out) */
         write_TDBR(drv_data, 0xFFFF);
@@ -474,13 +474,13 @@ static void u16_reader(struct driver_data *drv_data)
 
         while (drv_data->rx < (drv_data->rx_end - 2)) {
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
                 drv_data->rx += 2;
         }
 
         while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                continue;
+                cpu_relax();
         *(u16 *) (drv_data->rx) = read_SHAW(drv_data);
         drv_data->rx += 2;
 }
@@ -491,7 +491,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         /* clear TDBR buffer before read(else it will be shifted out) */
         write_TDBR(drv_data, 0xFFFF);
@@ -503,7 +503,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
                 cs_deactive(drv_data, chip);
 
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 cs_active(drv_data, chip);
                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
                 drv_data->rx += 2;
@@ -511,7 +511,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
         cs_deactive(drv_data, chip);
 
         while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                continue;
+                cpu_relax();
         *(u16 *) (drv_data->rx) = read_SHAW(drv_data);
         drv_data->rx += 2;
 }
@@ -520,15 +520,15 @@ static void u16_duplex(struct driver_data *drv_data)
 {
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         /* in duplex mode, clk is triggered by writing of TDBR */
         while (drv_data->tx < drv_data->tx_end) {
                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
                 while (read_STAT(drv_data) & BIT_STAT_TXS)
-                        continue;
+                        cpu_relax();
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
                 drv_data->rx += 2;
                 drv_data->tx += 2;
@@ -541,16 +541,16 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data)
 
         /* poll for SPI completion before start */
         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                continue;
+                cpu_relax();
 
         while (drv_data->tx < drv_data->tx_end) {
                 cs_active(drv_data, chip);
 
                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
                 while (read_STAT(drv_data) & BIT_STAT_TXS)
-                        continue;
+                        cpu_relax();
                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
-                        continue;
+                        cpu_relax();
                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
 
                 cs_deactive(drv_data, chip);
@@ -624,7 +624,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
 
         /* Wait for DMA to complete */
         while (get_dma_curr_irqstat(drv_data->dma_channel) & DMA_RUN)
-                continue;
+                cpu_relax();
 
         /*
          * wait for the last transaction shifted out.  HRM states:
@@ -635,11 +635,11 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
         if (drv_data->tx != NULL) {
                 while ((read_STAT(drv_data) & TXS) ||
                        (read_STAT(drv_data) & TXS))
-                        continue;
+                        cpu_relax();
         }
 
         while (!(read_STAT(drv_data) & SPIF))
-                continue;
+                cpu_relax();
 
         msg->actual_length += drv_data->len_in_bytes;
 
@@ -783,7 +783,7 @@ static void pump_transfers(unsigned long data)
 
                 /* poll for SPI completion before start */
                 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
-                        continue;
+                        cpu_relax();
 
                 /* dirty hack for autobuffer DMA mode */
                 if (drv_data->tx_dma == 0xFFFF) {