From: Lars Persson Date: Wed, 29 Jul 2015 07:32:02 +0000 (+0200) Subject: spi: Fix regression in spi-bitbang-txrx.h X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=26a67ec47a4c58fe79c6421c3dc3d697d322d2d6;p=linux-beck.git 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 --- 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--) {