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authorAnton Vorontsov <avorontsov@ru.mvista.com>2007-07-31 00:38:40 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-31 15:39:39 -0700
commit49bb23006b220c11bcf4e1d3eb99c289e6ab855e (patch)
treeb3852d2edebf7704c9662341e1cb886384a2a11c /drivers/spi
parent99eb8a550dbccc0e1f6c7e866fe421810e0585f6 (diff)
downloadop-kernel-dev-49bb23006b220c11bcf4e1d3eb99c289e6ab855e.zip
op-kernel-dev-49bb23006b220c11bcf4e1d3eb99c289e6ab855e.tar.gz
spi_mpc83xx: turn off SPI unit while switching mode
Documentation clearly states, that mode should not be changed till SPMODE_ENABLE bit set. I've seen hangs w/o this patch. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> 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/spi_mpc83xx.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 3295cfc..0b99fd9 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -176,6 +176,8 @@ static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
regval |= SPMODE_PM(pm);
}
+ /* Turn off SPI unit prior changing mode */
+ mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
if (mpc83xx_spi->activate_cs)
mpc83xx_spi->activate_cs(spi->chip_select, pol);
@@ -249,6 +251,8 @@ int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
regval &= 0xff0fffff;
regval |= SPMODE_LEN(bits_per_word);
+ /* Turn off SPI unit prior changing mode */
+ mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
return 0;
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