diff options
Diffstat (limited to 'nuttx')
| -rw-r--r-- | nuttx/ChangeLog | 2 | ||||
| -rw-r--r-- | nuttx/Documentation/NuttX.html | 4 | ||||
| -rw-r--r-- | nuttx/configs/mcu123-lpc214x/src/up_spi.c | 18 |
3 files changed, 17 insertions, 7 deletions
diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog index 9e5ef5b9b..a2c5b1e0d 100644 --- a/nuttx/ChangeLog +++ b/nuttx/ChangeLog @@ -528,5 +528,7 @@ 0.3.18 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr> * Added port for the STMicro STR71x processor and configuration for the Olimex STR-P711 board (untested as of the initial checkin). + * Fix race condition workaround delay in LPC214X SPI logic. It the cause of the very + bad MMC/SD performance. diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html index 34f9bee03..b56566e4f 100644 --- a/nuttx/Documentation/NuttX.html +++ b/nuttx/Documentation/NuttX.html @@ -8,7 +8,7 @@ <tr align="center" bgcolor="#e4e4e4"> <td> <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1> - <p>Last Updated: November 1, 2008</p> + <p>Last Updated: November 2, 2008</p> </td> </tr> </table> @@ -1114,6 +1114,8 @@ buildroot-0.1.0 2007-03-09 <spudmonkey@racsa.co.cr> nuttx-0.3.18 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr> * Added port for the STMicro STR71x processor and configuration for the Olimex STR-P711 board (untested as of the initial checkin). + * Fix race condition workaround delay in LPC214X SPI logic. It the cause of the very + bad MMC/SD performance. pascal-0.1.3 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr> diff --git a/nuttx/configs/mcu123-lpc214x/src/up_spi.c b/nuttx/configs/mcu123-lpc214x/src/up_spi.c index 9e201a5a0..0997aa01b 100644 --- a/nuttx/configs/mcu123-lpc214x/src/up_spi.c +++ b/nuttx/configs/mcu123-lpc214x/src/up_spi.c @@ -154,11 +154,16 @@ static void spi_select(FAR struct spi_dev_s *dev, boolean selected) while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF)); putreg16(0xff, LPC214X_SPI1_DR); - /* Then wait until TX FIFO and TX shift buffer are empty */ + /* Wait until TX FIFO and TX shift buffer are empty */ while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_BSY); + + /* Wait until RX FIFO is not empty */ + while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE)); + /* Then read and discard bytes until the RX FIFO is empty */ + do { (void)getreg16(LPC214X_SPI1_DR); @@ -290,7 +295,7 @@ static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const ubyte *buffer, siz } } - /* Then discard all card responses until the TX FIFO is emptied. */ + /* Then discard all card responses until the RX & TX FIFOs are emptied. */ do { @@ -304,12 +309,13 @@ static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const ubyte *buffer, siz (void)getreg16(LPC214X_SPI1_DR); } - /* There is a race condition where TFE may go FALSE just before - * RNE goes true. The nasty little delay in the following solves - * that (it could probably be tuned to improve performance). + /* There is a race condition where TFE may go TRUE just before + * RNE goes true and this loop terminates prematurely. The nasty little + * delay in the following solves that (it could probably be tuned + * to improve performance). */ - else if ((sr & LPC214X_SPI1SR_TFE) == 0) + else if ((sr & LPC214X_SPI1SR_TFE) != 0) { up_udelay(100); sr = getreg8(LPC214X_SPI1_SR); |