[PATCH 3.14 77/78] gpio: mcp23s08: Bug fix of SPI device tree registration.

Greg Kroah-Hartman
2014-06-09T22:56:42Z

From: Michael Welling <mwelling@ieee.org>

commit 99e4b98dbe3ad1fe38a74d12c3b8d44a55930de4 upstream.

The chips variable needs to be incremented for each chip that is
found in the spi_present_mask when registering via device tree.
Without this and the checking a negative index is passed to the
data->chip array in a subsequent loop.

Signed-off-by: Michael Welling <mwelling@ieee.org>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpio/gpio-mcp23s08.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/gpio/gpio-mcp23s08.c
+++ b/drivers/gpio/gpio-mcp23s08.c
@@ -895,8 +895,11 @@ static int mcp23s08_probe(struct spi_dev
return -ENODEV;
}

- for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++)
+ for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
pullups[addr] = 0;
+ if (spi_present_mask & (1 << addr))
+ chips++;
+ }
} else {
type = spi_get_device_id(spi)->driver_data;
pdata = dev_get_platdata(&spi->dev);
@@ -919,12 +922,12 @@ static int mcp23s08_probe(struct spi_dev
pullups[addr] = pdata->chip[addr].pullups;
}

- if (!chips)
- return -ENODEV;
-
base = pdata->base;
}

+ if (!chips)
+ return -ENODEV;
+
data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
GFP_KERNEL);
if (!data)