The patch titled Blackfin SPI driver: use cpu_relax() to replace continue in while busywait has been added to the -mm tree. Its filename is blackfin-spi-driver-use-cpu_relax-to-replace-continue-in-while-busywait.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: Blackfin SPI driver: use cpu_relax() to replace continue in while busywait From: Bryan Wu <bryan.wu@xxxxxxxxxx> Signed-off-by: Bryan Wu <bryan.wu@xxxxxxxxxx> Cc: David Brownell <david-b@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/spi/spi_bfin5xx.c | 78 ++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 39 deletions(-) diff -puN drivers/spi/spi_bfin5xx.c~blackfin-spi-driver-use-cpu_relax-to-replace-continue-in-while-busywait drivers/spi/spi_bfin5xx.c --- a/drivers/spi/spi_bfin5xx.c~blackfin-spi-driver-use-cpu_relax-to-replace-continue-in-while-busywait +++ a/drivers/spi/spi_bfin5xx.c @@ -186,7 +186,7 @@ static int flush(struct driver_data *drv /* 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_da 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_da 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 /* 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 driv /* 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 /* 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 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 driv /* 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 driv 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 driv 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 { /* 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 driv /* 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_dat /* 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 dri /* 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_dat /* 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_dat 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 dri /* 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 dri 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 dri 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_dat { /* 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 dri /* 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 i /* 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 i 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 /* 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) { _ Patches currently in -mm which might be from bryan.wu@xxxxxxxxxx are origin.patch git-mtd.patch blackfin-serial-driver-this-driver-enable-sports-on-blackfin-emulate-uart.patch kernel-printkc-concerns-about-the-console-handover.patch remove-mm_ptovvtop.patch spi-initial-bf54x-spi-support.patch spi-bfin-spi-uses-portmux-calls.patch spi-spi_bfin-cleanups-error-handling.patch spi-spi_bfin-handles-spi_transfercs_change.patch spi-spi_bfin-dont-bypass-spi-framework.patch spi-spi_bfin-uses-platform-device-resources.patch spi-spi_bfin-uses-portmux-for-additional-busses.patch spi-spi_bfin-rearrange-portmux-calls.patch spi-spi_bfin-change-handling-of-communication-parameters.patch spi-spi_bfin-relocate-spin-waits.patch spi-spi_bfin-handle-multiple-spi_masters.patch spi-spi_bfin-bugfix-for-816-bit-word-sizes.patch spi-spi_bfin-update-handling-of-delay-after-deselect.patch spi-spi_bfin-resequence-dma-start-stop.patch blackfin-spi-driver-use-cpu_relax-to-replace-continue-in-while-busywait.patch blackfin-spi-driver-use-void-__iomem-for-regs_base.patch blackfin-spi-driver-move-hard-coded-pin_req-to-board-file.patch blackfin-spi-driver-reconfigure-speed_hz-and-bits_per_word-in-each-spi-transfer.patch sanitize-the-type-of-struct-useru_ar0.patch add-cmpxchg_local-to-blackfin-replace-__cmpxchg-by-generic-cmpxchg.patch d_path-make-d_path-use-a-struct-path.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html