Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 26a67ec4 authored by Lars Persson's avatar Lars Persson Committed by Mark Brown
Browse files

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



This patch fixes a regression introduced by commit 232a5adc ("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: 232a5adc (spi: bitbang: only toggle bitchanges)
Signed-off-by: default avatarLars Persson <larper@axis.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
parent d770e558

drivers/spi/spi-bitbang-txrx.h

+2 −2
Original line number Diff line number Diff line
@@ -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--) {