The patch spi: sun4i: Prevent chip-select from being activated twice before a transfer has been applied to the spi tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 218e0b575ffe6de1c93249871b25bbf570fe1cb5 Mon Sep 17 00:00:00 2001 From: Marcus Weseloh <mweseloh42@xxxxxxxxx> Date: Tue, 5 Jan 2016 21:46:20 +0100 Subject: [PATCH] spi: sun4i: Prevent chip-select from being activated twice before a transfer The SPI core calls set_cs before a transfer, but the SUN4I_CTL_CS_MANUAL flag is only set in transfer_one. This leads to the following pattern on the chip-select line (with runtime power-management on every transfer, without it only on the first one): activate, deactivate, activate, transfer, deactivate Moving the configuration of the SUN4I_CTL_CS_MANUAL flag from transfer_one to set_cs removes the double activation. Signed-off-by: Marcus Weseloh <mweseloh42@xxxxxxxxx> Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/spi/spi-sun4i.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index fbb0a4d74e91..a6d936c68674 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -140,6 +140,9 @@ static void sun4i_spi_set_cs(struct spi_device *spi, bool enable) reg &= ~SUN4I_CTL_CS_MASK; reg |= SUN4I_CTL_CS(spi->chip_select); + /* We want to control the chip select manually */ + reg |= SUN4I_CTL_CS_MANUAL; + if (enable) reg |= SUN4I_CTL_CS_LEVEL; else @@ -222,9 +225,6 @@ static int sun4i_spi_transfer_one(struct spi_master *master, else reg |= SUN4I_CTL_DHB; - /* We want to control the chip select manually */ - reg |= SUN4I_CTL_CS_MANUAL; - sun4i_spi_write(sspi, SUN4I_CTL_REG, reg); /* Ensure that we have a parent clock fast enough */ -- 2.7.0.rc3 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html