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authorChristophe Leroy <christophe.leroy@c-s.fr>2018-12-07 13:07:55 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-29 13:40:15 +0100
commit1d060fede295f772f82f338fe2dcfe7daf41b3d5 (patch)
treea8d51f1720a0ed02982310be87e15b7e330fc92a
parent78d2d2762c6f05b62db4a0ec5c458f7b6e8114db (diff)
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>
-rw-r--r--drivers/gpio/gpio-max7301.c12
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;