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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>
This commit is contained in:
Jan Nikitenko 2008-07-24 01:27:07 +02:00 committed by Pierre Ossman
parent 20b7997e8a
commit 1685a03e98
1 changed files with 2 additions and 1 deletions
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3
drivers/mmc/host/mmc_spi.c
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@ -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");