| From 26a67ec47a4c58fe79c6421c3dc3d697d322d2d6 Mon Sep 17 00:00:00 2001 |
| From: Lars Persson <lars.persson@axis.com> |
| Date: Wed, 29 Jul 2015 09:32:02 +0200 |
| Subject: spi: Fix regression in spi-bitbang-txrx.h |
| |
| From: Lars Persson <lars.persson@axis.com> |
| |
| commit 26a67ec47a4c58fe79c6421c3dc3d697d322d2d6 upstream. |
| |
| 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 <larper@axis.com> |
| Signed-off-by: Mark Brown <broonie@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/spi/spi-bitbang-txrx.h | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- 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 |
| { |
| /* 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 |
| { |
| /* 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--) { |
| |
