Commit 1685a03e authored Jul 24, 2008 by Jan Nikitenko Committed by Pierre Ossman Jul 24, 2008

mmc_spi: put signals to low power off fix

The original intention was to write a zero byte to mmc to force spi
signals to low when doing power off. Somehow the spi_w8r8 call got there
so a read followed the write of single zero byte. This patch changes
that to simple write of zero byte without the following read.
This way the power off is more reliable and completely sufficient.

Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

parent 20b7997e

drivers/mmc/host/mmc_spi.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1076,6 +1076,7 @@ static void mmc_spi_set_ios(struct mmc_host mmc, struct mmc_ios ios)
		*/
		if (canpower && ios->power_mode == MMC_POWER_OFF) {
		int mres;
		u8 nullbyte = 0;

		host->spi->mode &= ~(SPI_CPOL\|SPI_CPHA);
		mres = spi_setup(host->spi);
		@@ -1083,7 +1084,7 @@ static void mmc_spi_set_ios(struct mmc_host mmc, struct mmc_ios ios)
		dev_dbg(&host->spi->dev,
		"switch to SPI mode 0 failed\n");

		if (spi_w8r8(host->spi, 0x00) < 0)
		if (spi_write(host->spi, &nullbyte, 1) < 0)
		dev_dbg(&host->spi->dev,
		"put spi signals to low failed\n");