From 26a67ec47a4c58fe79c6421c3dc3d697d322d2d6 Mon Sep 17 00:00:00 2001 From: Lars Persson Date: Wed, 29 Jul 2015 09:32:02 +0200 Subject: [PATCH] spi: Fix regression in spi-bitbang-txrx.h This patch fixes a regression introduced by commit 232a5adc5199 ("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: 232a5adc5199 (spi: bitbang: only toggle bitchanges) Signed-off-by: Lars Persson Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/spi/spi-bitbang-txrx.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-bitbang-txrx.h b/drivers/spi/spi-bitbang-txrx.h index 06b34e5bcfa3..47bb9b898dfd 100644 --- a/drivers/spi/spi-bitbang-txrx.h +++ b/drivers/spi/spi-bitbang-txrx.h @@ -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--) { -- 2.20.1