spi_mpc83xx: hang fix

When the spi_mpc83xx driver receives a tx_buf pointer which is NULL, it
only writes one zero filled word to the transmit register.  If the driver
expects to receive more than one word it will wait forever for a second
receive interrupt.  With this patch the controller will shift out zeroes
until all words have been received.

Signed-off-by: Jan Andersson <jan@gaisler.com>
Tested-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Andersson 2007-09-11 15:23:30 -07:00 committed by Linus Torvalds
parent 9c3013e9b9
commit 65e213cdb2

View File

@ -384,11 +384,8 @@ irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data)
mpc83xx_spi->count -= 1;
if (mpc83xx_spi->count) {
if (mpc83xx_spi->tx) {
u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
word);
}
u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
} else {
complete(&mpc83xx_spi->done);
}