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Commit d8c05008 authored by Bryan Wu's avatar Bryan Wu Committed by Linus Torvalds
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Blackfin SPI driver: use cpu_relax() to replace continue in while busywait 

Signed-off-by: default avatarBryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 07612e5f
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Showing with 39 additions and 39 deletions
drivers/spi/spi_bfin5xx.c
View file @ d8c05008
...@@ -186,7 +186,7 @@ static int flush(struct driver_data *drv_data) ...@@ -186,7 +186,7 @@ static int flush(struct driver_data *drv_data)
/* wait for stop and clear stat */ /* wait for stop and clear stat */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && limit--) while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && limit--)
continue; cpu_relax();
write_STAT(drv_data, BIT_STAT_CLR); write_STAT(drv_data, BIT_STAT_CLR);
...@@ -262,7 +262,7 @@ static void null_writer(struct driver_data *drv_data) ...@@ -262,7 +262,7 @@ static void null_writer(struct driver_data *drv_data)
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
write_TDBR(drv_data, 0); write_TDBR(drv_data, 0);
while ((read_STAT(drv_data) & BIT_STAT_TXS)) while ((read_STAT(drv_data) & BIT_STAT_TXS))
continue; cpu_relax();
drv_data->tx += n_bytes; drv_data->tx += n_bytes;
} }
} }
...@@ -274,7 +274,7 @@ static void null_reader(struct driver_data *drv_data) ...@@ -274,7 +274,7 @@ static void null_reader(struct driver_data *drv_data)
while (drv_data->rx < drv_data->rx_end) { while (drv_data->rx < drv_data->rx_end) {
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
dummy_read(drv_data); dummy_read(drv_data);
drv_data->rx += n_bytes; drv_data->rx += n_bytes;
} }
...@@ -287,12 +287,12 @@ static void u8_writer(struct driver_data *drv_data) ...@@ -287,12 +287,12 @@ static void u8_writer(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS) while (read_STAT(drv_data) & BIT_STAT_TXS)
continue; cpu_relax();
++drv_data->tx; ++drv_data->tx;
} }
} }
...@@ -303,14 +303,14 @@ static void u8_cs_chg_writer(struct driver_data *drv_data) ...@@ -303,14 +303,14 @@ static void u8_cs_chg_writer(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
cs_active(drv_data, chip); cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS) while (read_STAT(drv_data) & BIT_STAT_TXS)
continue; cpu_relax();
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
...@@ -325,7 +325,7 @@ static void u8_reader(struct driver_data *drv_data) ...@@ -325,7 +325,7 @@ static void u8_reader(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* clear TDBR buffer before read(else it will be shifted out) */ /* clear TDBR buffer before read(else it will be shifted out) */
write_TDBR(drv_data, 0xFFFF); write_TDBR(drv_data, 0xFFFF);
...@@ -334,13 +334,13 @@ static void u8_reader(struct driver_data *drv_data) ...@@ -334,13 +334,13 @@ static void u8_reader(struct driver_data *drv_data)
while (drv_data->rx < drv_data->rx_end - 1) { while (drv_data->rx < drv_data->rx_end - 1) {
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u8 *) (drv_data->rx) = read_RDBR(drv_data); *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
++drv_data->rx; ++drv_data->rx;
} }
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u8 *) (drv_data->rx) = read_SHAW(drv_data); *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
++drv_data->rx; ++drv_data->rx;
} }
...@@ -351,7 +351,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) ...@@ -351,7 +351,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* clear TDBR buffer before read(else it will be shifted out) */ /* clear TDBR buffer before read(else it will be shifted out) */
write_TDBR(drv_data, 0xFFFF); write_TDBR(drv_data, 0xFFFF);
...@@ -363,7 +363,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) ...@@ -363,7 +363,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
cs_active(drv_data, chip); cs_active(drv_data, chip);
*(u8 *) (drv_data->rx) = read_RDBR(drv_data); *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
++drv_data->rx; ++drv_data->rx;
...@@ -371,7 +371,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) ...@@ -371,7 +371,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u8 *) (drv_data->rx) = read_SHAW(drv_data); *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
++drv_data->rx; ++drv_data->rx;
} }
...@@ -380,15 +380,15 @@ static void u8_duplex(struct driver_data *drv_data) ...@@ -380,15 +380,15 @@ static void u8_duplex(struct driver_data *drv_data)
{ {
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* in duplex mode, clk is triggered by writing of TDBR */ /* in duplex mode, clk is triggered by writing of TDBR */
while (drv_data->rx < drv_data->rx_end) { while (drv_data->rx < drv_data->rx_end) {
write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS) while (read_STAT(drv_data) & BIT_STAT_TXS)
continue; cpu_relax();
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u8 *) (drv_data->rx) = read_RDBR(drv_data); *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
++drv_data->rx; ++drv_data->rx;
++drv_data->tx; ++drv_data->tx;
...@@ -401,16 +401,16 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data) ...@@ -401,16 +401,16 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
while (drv_data->rx < drv_data->rx_end) { while (drv_data->rx < drv_data->rx_end) {
cs_active(drv_data, chip); cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS) while (read_STAT(drv_data) & BIT_STAT_TXS)
continue; cpu_relax();
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u8 *) (drv_data->rx) = read_RDBR(drv_data); *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
...@@ -427,12 +427,12 @@ static void u16_writer(struct driver_data *drv_data) ...@@ -427,12 +427,12 @@ static void u16_writer(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
while ((read_STAT(drv_data) & BIT_STAT_TXS)) while ((read_STAT(drv_data) & BIT_STAT_TXS))
continue; cpu_relax();
drv_data->tx += 2; drv_data->tx += 2;
} }
} }
...@@ -443,14 +443,14 @@ static void u16_cs_chg_writer(struct driver_data *drv_data) ...@@ -443,14 +443,14 @@ static void u16_cs_chg_writer(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
cs_active(drv_data, chip); cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
while ((read_STAT(drv_data) & BIT_STAT_TXS)) while ((read_STAT(drv_data) & BIT_STAT_TXS))
continue; cpu_relax();
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
...@@ -465,7 +465,7 @@ static void u16_reader(struct driver_data *drv_data) ...@@ -465,7 +465,7 @@ static void u16_reader(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* clear TDBR buffer before read(else it will be shifted out) */ /* clear TDBR buffer before read(else it will be shifted out) */
write_TDBR(drv_data, 0xFFFF); write_TDBR(drv_data, 0xFFFF);
...@@ -474,13 +474,13 @@ static void u16_reader(struct driver_data *drv_data) ...@@ -474,13 +474,13 @@ static void u16_reader(struct driver_data *drv_data)
while (drv_data->rx < (drv_data->rx_end - 2)) { while (drv_data->rx < (drv_data->rx_end - 2)) {
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u16 *) (drv_data->rx) = read_RDBR(drv_data); *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
drv_data->rx += 2; drv_data->rx += 2;
} }
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u16 *) (drv_data->rx) = read_SHAW(drv_data); *(u16 *) (drv_data->rx) = read_SHAW(drv_data);
drv_data->rx += 2; drv_data->rx += 2;
} }
...@@ -491,7 +491,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) ...@@ -491,7 +491,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* clear TDBR buffer before read(else it will be shifted out) */ /* clear TDBR buffer before read(else it will be shifted out) */
write_TDBR(drv_data, 0xFFFF); write_TDBR(drv_data, 0xFFFF);
...@@ -503,7 +503,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) ...@@ -503,7 +503,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
cs_active(drv_data, chip); cs_active(drv_data, chip);
*(u16 *) (drv_data->rx) = read_RDBR(drv_data); *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
drv_data->rx += 2; drv_data->rx += 2;
...@@ -511,7 +511,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) ...@@ -511,7 +511,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u16 *) (drv_data->rx) = read_SHAW(drv_data); *(u16 *) (drv_data->rx) = read_SHAW(drv_data);
drv_data->rx += 2; drv_data->rx += 2;
} }
...@@ -520,15 +520,15 @@ static void u16_duplex(struct driver_data *drv_data) ...@@ -520,15 +520,15 @@ static void u16_duplex(struct driver_data *drv_data)
{ {
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* in duplex mode, clk is triggered by writing of TDBR */ /* in duplex mode, clk is triggered by writing of TDBR */
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS) while (read_STAT(drv_data) & BIT_STAT_TXS)
continue; cpu_relax();
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u16 *) (drv_data->rx) = read_RDBR(drv_data); *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
drv_data->rx += 2; drv_data->rx += 2;
drv_data->tx += 2; drv_data->tx += 2;
...@@ -541,16 +541,16 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data) ...@@ -541,16 +541,16 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
while (drv_data->tx < drv_data->tx_end) { while (drv_data->tx < drv_data->tx_end) {
cs_active(drv_data, chip); cs_active(drv_data, chip);
write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS) while (read_STAT(drv_data) & BIT_STAT_TXS)
continue; cpu_relax();
while (!(read_STAT(drv_data) & BIT_STAT_RXS)) while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue; cpu_relax();
*(u16 *) (drv_data->rx) = read_RDBR(drv_data); *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
cs_deactive(drv_data, chip); cs_deactive(drv_data, chip);
...@@ -624,7 +624,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) ...@@ -624,7 +624,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
/* Wait for DMA to complete */ /* Wait for DMA to complete */
while (get_dma_curr_irqstat(drv_data->dma_channel) & DMA_RUN) while (get_dma_curr_irqstat(drv_data->dma_channel) & DMA_RUN)
continue; cpu_relax();
/* /*
* wait for the last transaction shifted out. HRM states: * wait for the last transaction shifted out. HRM states:
...@@ -635,11 +635,11 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) ...@@ -635,11 +635,11 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
if (drv_data->tx != NULL) { if (drv_data->tx != NULL) {
while ((read_STAT(drv_data) & TXS) || while ((read_STAT(drv_data) & TXS) ||
(read_STAT(drv_data) & TXS)) (read_STAT(drv_data) & TXS))
continue; cpu_relax();
} }
while (!(read_STAT(drv_data) & SPIF)) while (!(read_STAT(drv_data) & SPIF))
continue; cpu_relax();
msg->actual_length += drv_data->len_in_bytes; msg->actual_length += drv_data->len_in_bytes;
...@@ -783,7 +783,7 @@ static void pump_transfers(unsigned long data) ...@@ -783,7 +783,7 @@ static void pump_transfers(unsigned long data)
/* poll for SPI completion before start */ /* poll for SPI completion before start */
while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
continue; cpu_relax();
/* dirty hack for autobuffer DMA mode */ /* dirty hack for autobuffer DMA mode */
if (drv_data->tx_dma == 0xFFFF) { if (drv_data->tx_dma == 0xFFFF) {
......
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