diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-12-07 13:07:55 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-29 13:39:09 +0100 |
| commit | 07cfa7ac9e52d3250061e3cb91acfecb905afefb (patch) | |
| tree | d4f08a5baaa4a7559fd34f5cbf8fa6e2d59fe2d1 /drivers | |
| parent | 4d7a081d0a35a2cd1908451edf66755914cc6ef1 (diff) | |
| download | linux-stable-07cfa7ac9e52d3250061e3cb91acfecb905afefb.tar.gz linux-stable-07cfa7ac9e52d3250061e3cb91acfecb905afefb.tar.bz2 linux-stable-07cfa7ac9e52d3250061e3cb91acfecb905afefb.zip | |
gpio: max7301: fix driver for use with CONFIG_VMAP_STACK
commit abf221d2f51b8ce7b9959a8953f880a8b0a1400d upstream.
spi_read() and spi_write() require DMA-safe memory. When
CONFIG_VMAP_STACK is selected, those functions cannot be used
with buffers on stack.
This patch replaces calls to spi_read() and spi_write() by
spi_write_then_read() which doesn't require DMA-safe buffers.
Fixes: 0c36ec314735 ("gpio: gpio driver for max7301 SPI GPIO expander")
Cc: <stable@vger.kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/gpio-max7301.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/drivers/gpio/gpio-max7301.c b/drivers/gpio/gpio-max7301.c index 05813fbf3daf..647dfbbc4e1c 100644 --- a/drivers/gpio/gpio-max7301.c +++ b/drivers/gpio/gpio-max7301.c @@ -25,7 +25,7 @@ static int max7301_spi_write(struct device *dev, unsigned int reg, struct spi_device *spi = to_spi_device(dev); u16 word = ((reg & 0x7F) << 8) | (val & 0xFF); - return spi_write(spi, (const u8 *)&word, sizeof(word)); + return spi_write_then_read(spi, &word, sizeof(word), NULL, 0); } /* A read from the MAX7301 means two transfers; here, one message each */ @@ -37,14 +37,8 @@ static int max7301_spi_read(struct device *dev, unsigned int reg) struct spi_device *spi = to_spi_device(dev); word = 0x8000 | (reg << 8); - ret = spi_write(spi, (const u8 *)&word, sizeof(word)); - if (ret) - return ret; - /* - * This relies on the fact, that a transfer with NULL tx_buf shifts out - * zero bytes (=NOOP for MAX7301) - */ - ret = spi_read(spi, (u8 *)&word, sizeof(word)); + ret = spi_write_then_read(spi, &word, sizeof(word), &word, + sizeof(word)); if (ret) return ret; return word & 0xff; |