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spi: Fix regression in spi-bitbang-txrx.h

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commit 26a67ec47a upstream.

This patch fixes a regression introduced by commit 232a5adc51 ("spi:
bitbang: only toggle bitchanges"). The attempt to optimize writes of
consecutive bit patterns broke most of the combinations of word size
and SPI modes due to selecting the wrong bit as the MSB value.

Fixes: 232a5adc51 (spi: bitbang: only toggle bitchanges)
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lars Persson
2015-07-29 09:32:02 +02:00
committed by Greg Kroah-Hartman
parent 7f3f69a695
commit 1583eaece6
1 changed files with 2 additions and 2 deletions
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4
drivers/spi/spi-bitbang-txrx.h
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@@ -49,7 +49,7 @@ bitbang_txrx_be_cpha0(struct spi_device *spi,
{
/* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */
bool oldbit = !(word & 1);
u32 oldbit = (!(word & (1<<(bits-1)))) << 31;
/* clock starts at inactive polarity */
for (word <<= (32 - bits); likely(bits); bits--) {
@@ -81,7 +81,7 @@ bitbang_txrx_be_cpha1(struct spi_device *spi,
{
/* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */
bool oldbit = !(word & (1 << 31));
u32 oldbit = (!(word & (1<<(bits-1)))) << 31;
/* clock starts at inactive polarity */
for (word <<= (32 - bits); likely(bits); bits--) {