diff options
| author | Kalle Valo <kalle.valo@nokia.com> | 2008-01-24 14:00:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-01-24 14:06:44 -0800 |
| commit | feed9bab7b14b77be8d796bcee95e2343fb82955 (patch) | |
| tree | d46191244459c4dd4c5f6e0ad0c832eaa7894af8 /drivers/spi | |
| parent | dbcc2ec60fe15448e5dfe4153f7347ac82b4da73 (diff) | |
| download | lwn-feed9bab7b14b77be8d796bcee95e2343fb82955.tar.gz lwn-feed9bab7b14b77be8d796bcee95e2343fb82955.zip | |
spi: omap2_mcspi PIO RX fix
Before transmission of the last word in PIO RX_ONLY mode rx+tx mode
is enabled:
/* prevent last RX_ONLY read from triggering
* more word i/o: switch to rx+tx
*/
if (c == 0 && tx == NULL)
mcspi_write_cs_reg(spi,
OMAP2_MCSPI_CHCONF0, l);
But because c is decremented after the test, c will never be zero and
rx+tx will not be enabled. This breaks RX_ONLY mode PIO transfers.
Fix it by decrementing c in the beginning of the various I/O loops.
Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/omap2_mcspi.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index 3cdab131c4a9..ea61724ae225 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -350,6 +350,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) tx = xfer->tx_buf; do { + c -= 1; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { @@ -380,7 +381,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) word_len, *(rx - 1)); #endif } - c -= 1; } while (c); } else if (word_len <= 16) { u16 *rx; @@ -389,6 +389,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) rx = xfer->rx_buf; tx = xfer->tx_buf; do { + c -= 2; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { @@ -419,7 +420,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) word_len, *(rx - 1)); #endif } - c -= 2; } while (c); } else if (word_len <= 32) { u32 *rx; @@ -428,6 +428,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) rx = xfer->rx_buf; tx = xfer->tx_buf; do { + c -= 4; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { @@ -458,7 +459,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) word_len, *(rx - 1)); #endif } - c -= 4; } while (c); } |